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2026-10-05net: make dev_xdp_sb_prog_count() see programs attached through a linkJakub Kicinski1-4/+7
ethtool refuses to enable tcp-data-split on a device running a single-buffer XDP program (which can't deal with the payload landing in a separate buffer). dev_xdp_sb_prog_count() only looks at xdp_state[].prog though, ignoring bpf_link integration. Get the prog pointer from dev_xdp_prog(), which will consult both. bpf_xdp_link_update() needs a bit of a touch-up, too, since ethtool calls dev_xdp_sb_prog_count() with just the instance lock (for ops-locked devices) - we now have to make sure the link updates happen under that lock. Spotted by AI while reviewing the XDP propagation series, verified and tested on netdevsim with a C test along these lines: link = bpf_program__attach_xdp(prog, ifindex); system("ethtool -G eth0 tcp-data-split on") Fixes: 197258f0ef68 ("net: ethtool: add hds_config member in ethtool_netdev_state") Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20261001012559.297751-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-29net: extend IPv6 exthdr detection of tunneled packetsWillem de Bruijn1-16/+31
Commit c4336a07eb6b ("net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback") split skb_gso_has_extension_hdr() into mutually exclusive branches on skb->encapsulation. This did not yet address all paths: 1. With skb->encapsulation set, the outer header is not checked. IPv6 tunnels such as ip6_gre and ip6_tunnel add an outer Destination Options header by default (encap_limit). Their GSO packets skip software GSO, then skb_csum_hwoffload_help() sees the outer extension header and calls skb_checksum_help() on the GSO skb, which warns and drops it. 2. Tunnels over IPv6 without an outer transport header, such as ip6_tunnel, leave skb->transport_header at the inner transport header. skb_network_header_len() then spans the outer IPv6, tunnel and inner IP headers, a false positive. 3. UDP tunnels without an inner network header, such as SCTP-in-UDP or PSP, have no inner IPv6 header to check. Decide on the outer header alone. 4. Directly dereferencing inner_ip_hdr(skb)->version without skb_header_pointer() is unsafe. Instead, check ipv6_ext_hdr(nexthdr) on the outer IPv6 header and, if set, on the inner IPv6 header. Read the headers with skb_header_pointer(). Keep the skb_network_header_len() check when !skb->encapsulation to also catch encapsulated packets without skb->encapsulation (e.g., virtio). Use the same helper in skb_csum_hwoffload_help(). Its open coded test has the false positive of (2) and ignores the inner header. Background: checksum offload of tunneled packets invariants: Non-GSO skb: - If the inner packet is CHECKSUM_PARTIAL, Local Checksum Offload computes the outer checksum in software and the device offloads only the inner L4 checksum. - If the inner packet is CHECKSUM_NONE (e.g., SCTP-in-UDP, ESP-in-UDP, Remote Checksum Offload), the device offloads the outer UDP or GRE checksum instead. GSO skb: - A device with NETIF_F_GSO_UDP_TUNNEL_CSUM or NETIF_F_GSO_GRE_CSUM computes both inner and outer checksums per segment. The outer checksum is seeded with only the pseudo-header checksum. A NETIF_F_IPV6_CSUM device must parse through the outer headers to reach the inner ones. Fixes: c4336a07eb6b ("net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback") Cc: stable@vger.kernel.org Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260926140506.2335137-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-29net: cap skb->queue_mapping when the tx queue is pickedJamal Hadi Salim1-7/+24
skbedit can set skb->queue_mapping and raise the per-CPU skip_txqueue flag so __dev_queue_xmit() honours the mapping. __dev_queue_xmit() cleared the flag before sch_handle_egress() and only read it afterwards, so the flag was not confined to the xmit that set it: a nested xmit (mirred redirect or mirror, or a drop after skbedit) could set the flag and the outer xmit would consume it for an skb that never went through skbedit. A forwarded packet still carries the ingress NIC's rx_queue + 1 in skb->queue_mapping, so the outer device then indexes its tx queue state with that stale value. Taprio's child array q->qdiscs[] is sized to the device's queue count, so taprio_enqueue() indexes past its allocation and dereferences the result as a struct Qdisc *. We (ab)use the skb->nf_skip_egress which means "skip netfilter egress for this packet" to tag to "am I in tc egress?". Despite the overload I dont see it as a conflict since the marker is set only around the single sch_handle_egress() call and ingress path is guarded by tc_at_ingress. I will send a followup(net-next) patch once this hits net-next to rename the skb->nf_skip_egress bit/flag to skb->skip_egress Arm the flag only from the egress classifier that can use it: raise skip_txqueue from tcf_skbedit_act() only when it runs inside sch_handle_egress(), thanks to skb->nf_skip_egress. An egress qdisc classifier runs in q->enqueue(), after the tx queue has been picked, so a mapping it sets cannot affect the current packet; arming the flag there only pollutes it for a later xmit. Then own the flag for the xmit frame the egress hook runs in: save the incoming value and clear it just before sch_handle_egress(), and restore it after the hook - on the consumed (drop) path, or, in the same call that reads it, on the surviving path. The save and the restores stay inside the egress_needed_key static branch, so a packet pays for them only when egress hooks are active (2f1e85b1aee4). Store the value netdev_cap_txqueue() selected back into skb->queue_mapping in netdev_tx_queue_mapping(), as netdev_core_pick_tx() already does, so the skip_txqueue path never hands a later reader on the xmit path a mapping the device cannot serve. A store made still later in the same frame, by a tc BPF program attached to a transmit qdisc, is outside this path and is not re-capped; a separate followup will resolve that path. netdev_xmit_skip_txqueue() returns the previous flag value so the save-and-clear is one call, and a no-op stub is provided when CONFIG_NET_EGRESS is disabled. skb->nf_skip_egress is compiled under CONFIG_NET_EGRESS rather than CONFIG_NETFILTER_SKIP_EGRESS, so skb_at_tc_egress() is valid whenever the egress path is built. A local user in a network namespace can redirect a packet from a device with more TX queues to one with fewer after setting a mapping valid only on the larger device. That reaches these reads and, under KASAN, faults with "slab-out-of-bounds in taprio_enqueue". Conditions to recreate the bug: the report's own trigger is a local user with CAP_NET_ADMIN in a network namespace, so no eBPF program is needed. With CONFIG_NET_SCH_TAPRIO=y, CONFIG_NET_ACT_SKBEDIT=y, CONFIG_NET_ACT_MIRRED=y, CONFIG_NET_CLS_MATCHALL=y, CONFIG_NET_SCH_PRIO=y and KASAN enabled, create qa (3 queues), qb (2 queues) and qc (1 queue) as dummy devices; put a taprio root on qb (num_tc 1, queues 2@0) and clsact on all three; then add an egress matchall filter on every device. On qa: "action skbedit queue_mapping 2 pipe action mirred egress redirect dev qb". On qb: "action mirred egress mirror dev qc". On qc: "action skbedit queue_mapping 0 pipe". Send one packet out qa. qc's skbedit sets the flag while qb's outer xmit is in flight; without the fix qb consumes it and reads its two-entry taprio child array with the forwarded packet's stale mapping. A qc whose skbedit is instead installed in a transmit-qdisc classifier (a matchall filter on the qc root qdisc) reaches the same code path the same way without the fix. Testing: on a KASAN build with panic_on_warn=1 the unfixed kernel panics with "BUG: KASAN: slab-out-of-bounds in taprio_enqueue", a read 0 bytes past a 16-byte taprio_init() allocation, for the clsact-setter and the transmit-qdisc-classifier reproducers and for a clsact skbedit-then-tc-BPF store; the fixed kernel runs all three with no report, and the BPF store variant additionally shows the expected "selects TX queue" clamp notice from the write-back. Fixes: 2f1e85b1aee4 ("net: sched: use queue_mapping to pick tx queue") Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com> Link: https://lore.kernel.org/netdev/CANn89iLwYx8nCVf0pCEk_MmEiyC6kQaMwCQT9WkQVeeNzNQHqQ@mail.gmail.com/ Link: https://lore.kernel.org/netdev/179008581937.2160803.7117814290574262942@kernel.org/ Link: https://lore.kernel.org/netdev/179033713973.2160803.4914570693994398206@kernel.org/ Link: https://lore.kernel.org/netdev/20260925180407.63647514@kernel.org/ Link: https://lore.kernel.org/netdev/CANn89i+k-mZKDQVtvws_MEXeuMTAdaCcOXFZE-RfhcGTu90sjA@mail.gmail.com/ Suggested-by: Eric Dumazet <edumazet@google.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Tested-by: hybris <hybris@mojatatu.ai> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/QDISC-9R8V.v4.20260928081529@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-29net: fix checksum offsets in skb_splice_from_iter()Alireza Asgari1-3/+5
skb_splice_from_iter() appends multiple page fragments before updating skb->len. However, skb_splice_csum_page() uses that unchanged length as the offset for every fragment checksum. If bytes already appended during the call have an odd total length, a later fragment's checksum is combined with the wrong parity. For example, prime a UDP socket with sendto(MSG_MORE) and splice two distinct pipe buffers containing "abc" and "DEFGH". Uncorking reports success, but the receiver discards the packet for a bad checksum. This also affects IPv6 and fragments beginning near a page boundary. Pass the initial skb length plus the bytes already spliced to the checksum helper. Keep the existing final length update and partial-progress error handling unchanged. CHECKSUM_PARTIAL does not use this helper and remains unaffected. Fixes: 2e910b95329c ("net: Add a function to splice pages into an skbuff for MSG_SPLICE_PAGES") Cc: stable@vger.kernel.org Signed-off-by: Alireza Asgari <alireza@asgari.net> Link: https://patch.msgid.link/20260924-fix-udp-splice-checksum-v1-1-fe61d65447a8@asgari.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-29net: gso: limit recursive IP-in-IP segmentationZihan Xi1-0/+1
IP-in-IP GSO can re-enter inet_gso_segment() or ipv6_gso_segment() for each nested IP header. encap_level tracks header bytes, not callback depth, so a deep chain can exhaust the kernel stack. Making inet_gso_segment() stackable introduced unbounded IPv4 nesting; IPIP GSO/TSO later made the path reachable. The IPv6 stackable path was introduced separately and uses the same guard. Count IPv4 and IPv6 GSO handler entries in skb_gso_cb, initialized once per top-level GSO operation and preserved across GRE/UDP context changes. Use the existing IP_TUNNEL_RECURSION_LIMIT for both handlers. The first five entries pass, and the sixth returns -EINVAL before dispatching another GSO callback. Fixes: 3347c9602955 ("ipv4: gso: make inet_gso_segment() stackable") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Closes: https://lore.kernel.org/all/cover.1790157745.git.zihanx@nebusec.ai/ Assisted-by: LLM Co-developed-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Luxing Yin <root@tr0jan.top> Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260924051521.32568-2-zihanx@nebusec.ai Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-09-28net: restrict SO_RESERVE_MEM to TCP sockets and cap max valueEric Dumazet1-2/+2
Commit 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM") and commit d00c8ee31729 ("net: fix possible NULL deref in sock_reserve_memory") only checked sk_has_account(sk), which is true for both TCP and UDP sockets. However, SO_RESERVE_MEM and sk_unused_reserved_mem() are currently only supported by TCP: - On UDP sockets, sk->sk_forward_alloc is protected by sk->sk_receive_queue.lock, whereas sock_reserve_memory() and sock_release_reserved_memory() only acquire lock_sock(sk). Concurrent UDP packet reception/release and setsockopt(SO_RESERVE_MEM) corrupt sk_forward_alloc and memcg accounting. - udp_rmem_release() reclaims excess sk_forward_alloc without accounting for sk_unused_reserved_mem(sk). Restrict sock_reserve_memory() to TCP sockets (sk_is_tcp(sk)) for now. Supporting SO_RESERVE_MEM for UDP (acquiring sk_receive_queue.lock and honoring sk_unused_reserved_mem() in udp_rmem_release()) can be done in a future net-next series if needed. In addition, reject val > SZ_1G with -EINVAL in sk_setsockopt(SO_RESERVE_MEM). Without an upper bound, values near INT_MAX cause sk_mem_pages(delta) and (pages << PAGE_SHIFT) to overflow 32-bit signed int, corrupting sk->sk_forward_alloc and sk->sk_reserved_mem. Using a page-aligned cap (SZ_1G) ensures that the page-rounded sk->sk_reserved_mem reported by getsockopt(SO_RESERVE_MEM) can always be passed back to setsockopt(SO_RESERVE_MEM). Fixes: 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM") Reported-by: Cai Xinchen <caixinchen1@huawei.com> Closes: https://lore.kernel.org/netdev/5a88421d-10ef-4fca-9acb-85a27a3c1173@huawei.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Link: https://patch.msgid.link/20260925135244.3715196-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28net: ethtool: let tsconfig reach a PHY-only timestamp providerNicolai Buchwitz1-1/+2
TSCONFIG_GET and TSCONFIG_SET reject a device that implements neither hwtstamp NDO, even when its PHY can serve the request. The ioctls they meant to replace handle it, so the two interfaces disagree on the same hardware and user space has to pick one. Accept the default timestamping PHY and an already installed provider on both sides. On the set side the test moves into ethnl_set_tsconfig() as the validate callback runs without rtnl. On the get side it stays ahead of ethnl_ops_begin(), so a device that can serve nothing keeps failing with EOPNOTSUPP and a dump still skips it rather than stopping there. A netdev provider needs ndo_hwtstamp_set to be programmed at all, so don't pick that source without it, and test for ndo_hwtstamp_get before calling it. Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config") Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Reviewed-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20260925135237.3432266-3-nb@tipi-net.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28net: page_pool: fix use-after-free in page_pool_recycle_ring_bulk()Mina Almasry1-1/+1
With CONFIG_PAGE_POOL_STATS=y, page_pool_recycle_ring_bulk() updates the recycle stats after dropping the producer lock. If it just recycled the last inflight netmems of a pool being destroyed, page_pool_release() can pass its producer-lock barrier and free the pool before recycle_stat_add() runs. Commit fcc680a647ba7 ("page_pool: allow mixing PPs within one bulk") moved this stat update after the unlock. Commit 271683bb2cf32 ("page_pool: Fix use-after-free in page_pool_recycle_in_ring") later added the barrier, but only fixed page_pool_recycle_in_ring(). Move the update back under the lock. Fixes: fcc680a647ba7 ("page_pool: allow mixing PPs within one bulk") Link: https://lore.kernel.org/r/179028939171.2160803.706522228583664641@kernel.org Cc: Kaifeng Wang <kaifengw@google.com> Cc: Dong Chenchen <dongchenchen2@huawei.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260925144127.1445667-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-24Merge tag 'net-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds5-35/+68
Pull networking fixes from Jakub Kicinski: "Including fixes from Bluetooth, NFC and Netfilter. Every week in this release is record-setting for number of posted patches. It doesn't seem like we're creating any regressions with all these fixes, three 'Fixes' tags here point to 7.2 commits but none are true regression fixes. We're trying to keep the count down, nonetheless. Previous releases - regressions: - net: don't require the hwtstamp NDOs when a PHY provides timestamping - ipv6: fix dst leak for uncached routes - vrf: stop corrupting skb->csum when capturing CHECKSUM_COMPLETE packets Previous releases - always broken: - packet: use ubuf_info completion for TX_RING packets - arp: terminate device name before lookup - ipv6: do not let ipv6_find_hdr() return an offset past the packet end - udp: remove a disconnected socket from the 4-tuple hash table - sctp: discard the rest of the packet on a stale-cookie error - eth: mlx5: Bridge, fix remaining switchdev ownership gaps on merged eswitch" [ And lots of other random network driver fixes ] * tag 'net-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (189 commits) tcp: prevent collapsing skbs across boundary in rtx queue vlan: ensure sufficient headroom in vlan_dev_hard_header() net/sched: sch_teql: fix shadowed err in __teql_resolve() bridge: check llc_mac_hdr_init() return value in br_send_bpdu() llc: fix skb UAF and leaks on llc_mac_hdr_init() failure llc: reserve device headroom for allocated frames gve: DQO: reject TSO packets with an out of range MSS gve: fix TX drop when GSO MSS is too small for hw gve: DQO: fix header length used by gve_can_send_tso() for UDP GSO net: flush skb_defer_nodes in dev_cpu_dead() net: ethernet: stmmac: dwmac-rk: fix bulk clock leak when the PHY clock fails af_packet: fix integer overflow in prb_calc_retire_blk_tmo() tipc: Fix a data race on mon->peer_cnt in mon_timeout() net: phy: intel-xway: workaround 100BASE-TX Link-Up issue net/smc: fix UAF on lgr list traversal in smcr_port_err() net/rds: size a connection's path set by the transport it ends up with nfp: hold IPsec RX state under the XArray lock net: ena: fix MMIO read buffer leak on probe failure net: ena: fix PHC cleanup on probe failure net/sched: act_ct: fix helper UAF due to extensions realloc ...
2026-09-24net: flush skb_defer_nodes in dev_cpu_dead()Eric Dumazet3-15/+46
When a CPU goes offline, dev_cpu_dead() drains its softnet queues (completion_queue, output_queue, poll_list, process_queue, and input_pkt_queue), but leaves net_hotdata.skb_defer_nodes untouched. If oldcpu goes offline while holding pending skbs in its skb_defer_nodes lists (e.g. below the sysctl_skb_defer_max >> 1 IPI threshold, or if the IPI races with CPU teardown), those skbs remain stranded until oldcpu is brought back online. If any of these skbs hold page_pool fragments, page_pool_destroy() will stall indefinitely waiting for inflight pages to be returned when a netdev or driver is torn down while oldcpu is offline. Additionally, if smp_call_function_single_async() fails in kick_defer_list_purge() because the target CPU went offline, reset defer_ipi_scheduled to 0 so future IPI kicks are not blocked when the CPU comes back online. Also, if oldcpu was the last online CPU on its NUMA node, drain that node's slot across all CPUs so no skbs deferred from that node remain stranded on idle remote CPUs (or if the node itself is subsequently offlined). Finally, in skb_attempt_defer_free(), re-check cpu_online(cpu) and whether the caller migrated CPUs after llist_add(), flushing the node list if so, to close the preemption TOCTOU race against CPU/node teardown. Fixes: 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") Fixes: 5628f3fe3b16 ("net: add NUMA awareness to skb_attempt_defer_free()") Closes: https://lore.kernel.org/netdev/20260916003430.3612956-1-kris.pan@intel.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kris Pan <kris.pan@intel.com> Link: https://patch.msgid.link/20260923130318.607255-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-24Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds3-25/+26
Pull bpf fixes from Alexei Starovoitov: - Fix bpf_skb_change_tail() to drop the checksum offload instead of rejecting the trim of CHECKSUM_PARTIAL skbs (Daniel Borkmann) - Add KF_PERFMON kfunc flag and require CAP_PERFMON for kfuncs that read arbitrary memory and for untrusted read-only memory reads (Daniel Borkmann) - Clear scalar delta on narrowing stack spill (Daniel Borkmann) - Set up the frame pointer for the exception callback in arm64 JIT, and zero-fill other CPUs when BPF_F_CPU update creates a per-cpu hash element (Donggeun Yoo) - Various fixes (Emil Tsalapatis): - Fix bounds check underflow for skb-backed dynptrs - Fix rx_queue_mapping context access code generation in bpf_sock - Reject packet pointer arguments to subprogs that may mutate the packet - Reject ALU instructions that see arena and non-arena operands on different code paths - Fix copied_seq double-counting on sockmap self-redirect (Geliang Tang) - Fix divide-by-zero in btf_struct_walk() on a flexible array of zero-sized elements, fix out-of-bounds read of rtt_min in sock_ops (Jiayuan Chen) - Fix bpf_sock_destroy() out-of-bounds read of sk_protocol on TIME_WAIT and request socks, and sleeping under RCU when destroying a listener with pending children (Jiayuan Chen) - Fix JEQ/JNE with immediate operand in MIPS32 JIT and missing zero extension of BSWAP 16/32 in MIPS64 JIT (Johan Almbladh) - Avoid soft lockup in htab lookup[_and_delete] batch operations on large maps (Jose Fernandez) - Various fixes (Kumar Kartikeya Dwivedi): - Verify global subprogs in each sleepability context they are called from - Make post-verification instruction rewrites killable - Preserve packet pointer displacement in regsafe() - Apply CO-RE relocations before subprogram validation, restrict CO-RE poisoning to relocatable instructions, and reject truncated ldimm64 CO-RE relocations in libbpf - Assign lock identity to callback map values - Compare stack frames in regs_exact() - Bound ownership depth through local kptrs and graph roots - Fix u32 overflow in map batch operations when the map size exceeds 4GB (Masoud Aghasi) - Fix UAF in bpf memalloc due to concurrent consumption of ttrace lists in alloc_bulk() (Pu Lehui) - Allow gotox as the terminal instruction of a program or a subprogram (Siddharth Chintamaneni) - Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL, skip unsettled links in link iterator, and reject dev-bound-only programs on other devices (Weiming Shi) - Reject non-negative stack offsets in stack_slot_obj_get_spi() (Xu Yunxiang) - Check params size before reading reserved fields in bpf_crypto_ctx_create() (Yuqi Xu) - Reject max_entries > INT_MAX in sock_map_alloc() (Zhao Gongyi) - Use a 32-bit compare in xsk_map_gen_lookup() (Zhiling Zou) - Use kvfree() in xdp_test_run_teardown() (Zhixing Chen) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (58 commits) selftests/bpf: Test per-cpu initialization of a BPF_F_CPU created element bpf: Zero-fill other CPUs when BPF_F_CPU creates a per-cpu hash element bpf: Fix BSWAP 32 and 16 on MIPS64 bpf: Fix immediate JMP JEQ/JNE on MIPS32 bpf: Reject dev-bound-only programs on other devices bpf, sockmap: Reject max_entries > INT_MAX in sock_map_alloc selftests/bpf: Test for mixed arena/nonarena code paths bpf: Prevent variable arena/non-arena register contents selftests/bpf: Test rejection of pkt args to mutating subprogs bpf: Reject pkt arguments in mutating subprogs selftests/bpf: Add selftests for rx_queue_mapping context access bpf: Fix bpf_sock context code generation selftests/bpf: Test dynptr slices past end of skb bpf: Fix bounds check for skb-backed dynptrs selftests/bpf: Reject iterator destruction through fp+0 bpf: Reject non-negative offsets in stack_slot_obj_get_spi() bpf: Check params size before reading reserved fields selftests/bpf: Check local object ownership depth bpf: Bound ownership depth through local kptrs and graph roots selftests/bpf: Cover frame changes in bounded loops ...
2026-09-23net: xps: reject an out of range traffic classNorbert Szetei1-1/+1
Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store (net/core/net-sysfs.c:1880) netdev_queue_attr_store (net/core/net-sysfs.c:1390) Allocated by task 634: __kmalloc_noprof (mm/slub.c:5439) __netif_set_xps_queue (net/core/dev.c:2937) The buggy address is located 0 bytes to the right of allocated 88-byte region [ffff88813016bc00, ffff88813016bc58) Reject a class the map has no room for. Fixes: 184c449f91fe ("net: Add support for XPS with QoS via traffic classes") Signed-off-by: Norbert Szetei <norbert@doyensec.com> Link: https://patch.msgid.link/162DD16F-54C6-444A-9E09-0B8CB3D591F2@doyensec.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-23net: skbuff: fix pull-bound underflow in skb_checksum_setup_ipv6()Shihuang Liu1-3/+6
skb_maybe_pull_tail() subtracts skb_headlen(skb) from the unsigned max argument and passes the result to __pskb_pull_tail() as a signed int. The function does not ensure that max is at least skb_headlen(skb). This can happen while parsing IPv6 extension headers when an skb already has a linear area larger than MAX_IPV6_HDR_LEN. Once the parser needs data beyond the linear area, max - skb_headlen(skb) wraps and is converted to a negative delta. __pskb_pull_tail() then passes that negative length to skb_copy_bits(), where it can become a very large copy length. Pass the requested length itself as the pull bound at the three extension-header call sites, so the delta can no longer go negative. Fixes: 1431fb31ecba ("xen-netback: fix fragment detection in checksum setup") Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Shihuang Liu <shlomojune6@gmail.com> Link: https://patch.msgid.link/20260919133604.50948-1-shlomojune6@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-22net: devmem: document that bind-tx is unprivileged by designMina Almasry1-0/+6
Unlike bind-rx, which configures shared NIC RX queues to steer incoming traffic into the caller's dmabuf and requires CAP_NET_ADMIN (uns-admin-perm), bind-tx only DMA-maps the caller's dmabuf so the caller can transmit from it on their own sockets without affecting other traffic or device configuration. Add a comment in netdev.yaml and above netdev_nl_bind_tx_doit() to make it explicit that NETDEV_CMD_BIND_TX is unprivileged by design. Signed-off-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/20260921195545.493253-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-22bpf, sockmap: Reject max_entries > INT_MAX in sock_map_allocZhao Gongyi1-0/+1
sock_map_alloc() only rejects max_entries == 0 and otherwise allows any u32 value. sock_map_free() then walks the sks[] array with a signed int iterator: int i; for (i = 0; i < stab->map.max_entries; i++) struct sock **psk = &stab->sks[i]; When a SOCKMAP is created with max_entries = 0xffffffff (UINT_MAX), the allocation of 32 GiB can succeed on large-memory hosts. During free the counter reaches 0x80000000, wraps to INT_MIN, is sign-extended by movslq and turned into a ~16 GiB negative offset from stab->sks, pointing far below the allocation. The faulting access is an xchg() write in sock_map_free(). Without KASAN, the same out-of-bounds write can fault on an unmapped vmalloc page or corrupt an unrelated allocation if that vmalloc address is populated. On a KASAN kernel with CONFIG_KASAN_VMALLOC=y, the shadow check for that address hits an unmapped shadow page and oopses first: BUG: unable to handle page fault for address: fffff521b59c5a00 RIP: 0010:kasan_check_range+0x107/0x190 Call Trace: sock_map_free+0x93/0x190 map_create+0x68d/0xb30 __sys_bpf+0x21e/0x2e70 Vmcore confirmed stab->map.max_entries == 0xffffffff, stab->sks == 0xffffc911ace2d000, and the faulting address sks + (s64)INT_MIN * 8 exactly at 0xffffc90dace2d000. The same buggy path is reached on the normal close()/bpf_map_free_deferred() path whenever such a map is destroyed. sock_map_alloc() used to bound its allocation size through bpf_map_charge_init(), but the bound was dropped when rlimit-based memory accounting was removed. Reject max_entries > INT_MAX at creation time so the signed iterator in sock_map_free() never sees a value that would overflow. Triggered by syzkaller and reproduced on both a 6.6-based KASAN kernel and the upstream v7.3-rc2 kernel. Fixes: 0d2c4f964050 ("bpf: Eliminate rlimit-based memory accounting for sockmap and sockhash maps") Signed-off-by: Zhao Gongyi <zhaogongyi@BYTEDANCE.COM> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://patch.msgid.link/20260917121016.48171-1-zhaogongyi@bytedance.com
2026-09-22bpf: Fix bpf_sock context code generationEmil Tsalapatis1-3/+4
Currently, the ctx access code reads the rx_queue_mapping field with either a 4-byte or 2-byte load. The rest of the bits in the register are marked known zero by the verifier. However, the emitted ctx access code places in the register on certain the special value (-1) using BPF_MOV_IMM64, which gets sign-extended to turn on all the bits in the register. By shifting this value right, the program ends up with a value at runtime above what the verifier assumes is possible. Fix this by ensuring the read value is as wide as the assumed size. Use MOV32 instructions instead of MOV64 instructions to keep the upper bits zero as assumed by the verifier. Also properly report the size of the destination variable (the bpf_sock field, 4 bytes) instead of the source (the socket field, 2 bytes). Fixes: c3c16f2ea6d2 ("bpf: Add rx_queue_mapping to bpf_sock") Reported-by: Nicholas Carlini <nicholas@carlini.com> Suggested-by: Nicholas Carlini <nicholas@carlini.com> Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20260922172028.6269-4-emil@etsalapatis.com
2026-09-21net: don't require the hwtstamp NDOs when a PHY provides timestampingNicolai Buchwitz1-16/+9
Removing the legacy ioctl fallback made both hwtstamp NDOs mandatory. A device that only timestamps in its PHY implements neither, so SIOCSHWTSTAMP fails with EOPNOTSUPP before anything looks at the PHY and PTP stops working there. The check only ever picked the legacy path. That path is gone, so drop it and test where the NDOs are actually called. SIOCGHWTSTAMP is new here, not restored. The old path went through phy_mii_ioctl(), which only handled SIOCSHWTSTAMP. Such a device now returns -ENODEV while absent instead of -EOPNOTSUPP, like the ones that do implement the NDOs. Fixes: 5062245a5a7f ("net: remove legacy way to get/set HW timestamp config") Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de> Reviewed-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://patch.msgid.link/20260918095540.34286-1-nb@tipi-net.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-17net: skbuff: do not leave stale header offsets after pskb_carve()Eric Dumazet1-2/+30
pskb_carve_inside_header() and pskb_carve_inside_nonlinear() remove the first bytes of a packet and reallocate skb->head. All the headers that were present before the operation are gone, but both functions call skb_headers_offset_update(skb, 0), which is a no-op : skb->mac_header, skb->network_header, skb->transport_header and skb->csum_start keep their old values and now describe bytes which are no longer there. Both helpers size the new head from the old skb_end_offset(), so the stale offsets still land inside the new allocation. They point past skb_tail_pointer() though, to bytes that were never initialized. pskb_carve_inside_nonlinear() is the worst case, because it leaves a zombie skb with an empty linear part (skb->data == skb_tail_pointer(skb), skb_headlen(skb) == 0), while skb_mac_header_was_set() is still true and skb->mac_header is way ahead of skb->data. The only user of pskb_extract() is rds_tcp_data_recv(), and the carved skb is queued on tinc->ti_skb_list. When the RDS incoming message is released, rds_tcp_inc_free() calls skb_queue_purge(), which frees the skbs with SKB_DROP_REASON_QUEUE_PURGE. This is visible from drop_monitor, which then tries to pull back to the (bogus) mac header : skbuff: __skb_pull(len=234) skb len=6968 data_len=6968 headroom=0 headlen=0 tailroom=0 end-tail=384 mac=(234,14) mac_len=14 net=(248,40) trans=288 shinfo(txflags=0 nr_frags=1 gso(size=1428 type=16 segs=5)) csum(0x100120 start=288 offset=16 ip_summed=3 complete_sw=0 valid=1 level=0) hash(0x7b446c6c sw=0 l4=1) proto=0x86dd pkttype=0 iif=60 kernel BUG at ./include/linux/skbuff.h:2847! Add skb_carve_reset_headers() to mark the mac and transport headers as not set, reset the network header, clear skb->mac_len, and drop a now meaningless CHECKSUM_PARTIAL (csum_start no longer describes anything). Invalidate the inner offsets as well. Unlike mac_header and transport_header they have no "unset" sentinel, so a leftover non-zero value still looks like a real header. Zero skb->inner_mac_header, skb->inner_network_header, skb->inner_transport_header, skb->inner_protocol and skb->encapsulation, so that all the header state is invalidated in one place. v2: fixed an inaccurate changelog. The stale offsets stay inside the new skb->head, which is never smaller than the old one, they simply point past skb_tail_pointer() to bytes that are gone. Thanks to Xuanqiang Luo for insisting on this. Also invalidate the inner header state, as suggested by the netdev AI review : https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260911114922.621937-1-edumazet%40google.com Fixes: 6fa01ccd8830 ("skbuff: Add pskb_extract() helper function") Reported-by: syzbot+586af68eb819833c2d91@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6aa3e9d3.f2639fcc.29487d.0028.GAE@google.com/ Cc: Xuanqiang Luo <xuanqiang.luo@linux.dev> Cc: Allison Henderson <achender@kernel.org> Cc: rds-devel@oss.oracle.com Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Link: https://patch.msgid.link/20260915130423.3956471-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-09-16net: psp: avoid conflicts with skb->decrypted and sk_validate_xmit_skb()Daniel Zahka1-0/+7
PSP conflicts with TLS ULP in its usage of both skb->decrypted and sk->sk_validate_xmit_skb(). Make PSP mutually exclusive with TLS ULP, the only other user of either of these. As other users of skb->decrypted come along, they can be added to sk_has_decrypt_user(). It would make sense to also assert that sk->sk_validate_xmit_skb() is also NULL in both of these setup paths for similar future proofing, but the PSP listener/sk_clone() path is still broken and it could be seen as a regression to not allow rx assoc to run on a child of a listener socket with PSP tx assoc state. Include all TCP ULPs in the sk_has_decrypt_user() check, even though TLS is the only one that conflicts with PSP via the decrypted bit. This is intentional because PSP was not designed to be used with ULPs. It is best to close off surface area that may make bugs reachable, until someone wishes to design and test an actual user of PSP with ULPs. Fixes: 6b46ca260e22 ("net: psp: add socket security association code") Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260915-psp-ktls-fix-v2-1-0eedc3b148ec@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-16net: lock the socket in sock_gettstamp()Eric Dumazet1-1/+8
sk->sk_flags must only be changed while holding the socket lock, because sock_set_flag() and sock_reset_flag() use non atomic operations (__set_bit() and __clear_bit()). sock_gettstamp() is one of the last places where a bit of sk->sk_flags is changed from a syscall without owning the socket lock, through sock_enable_timestamp(sk, SOCK_TIMESTAMP). sk_set_memalloc() and sk_clear_memalloc() also change sk->sk_flags without the socket lock, but their callers (nbd, iscsi_tcp, nvme-tcp, sunrpc, wireguard) need a careful audit, this will be addressed in a separate patch. Jungwoo Lee and Wongi Lee reported an UDP socket use-after-free caused by this bug: a SIOCGSTAMPNS_NEW ioctl racing with bind() can cancel the SOCK_RCU_FREE bit that udp_lib_get_port() just set, because both threads perform a read-modify-write on the same word. CPU 0 (bind) CPU 1 (SIOCGSTAMPNS_NEW) -------------------------------- ---------------------------- read sk_flags = F read sk_flags = F compute F | BIT(SOCK_RCU_FREE) compute F | BIT(SOCK_TIMESTAMP) store F | BIT(SOCK_RCU_FREE) sk_add_node_rcu(sk, ...) store F | BIT(SOCK_TIMESTAMP) After the lost update, SOCK_RCU_FREE is clear while the socket is visible to lockless UDP receive lookups. sk_destruct() then frees the socket immediately instead of waiting for a RCU grace period, while the receive path still holds a reference-less pointer to it: BUG: KASAN: slab-use-after-free in ipv4_pktinfo_prepare+0x30/0x410 Read of size 8 at addr ffff888008806610 by task exploit/207 CPU: 0 UID: 1000 PID: 207 Comm: exploit Not tainted 6.12.95+ #1 ipv4_pktinfo_prepare+0x30/0x410 udp_queue_rcv_one_skb+0x51c/0x1180 udp_unicast_rcv_skb+0x109/0x350 ip_protocol_deliver_rcu+0x14b/0x310 ip_local_deliver_finish+0x29d/0x390 ip_local_deliver+0x24d/0x2a0 Only grab the socket lock when SOCK_TIMESTAMP has to be set, to keep the common case lockless. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Jungwoo Lee <jwlee2217@gmail.com> Reported-by: Wongi Lee <qw3rtyp0@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260915043055.3441600-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-16net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop checkFarhad Alemi1-1/+1
ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the route to the tunnel's remote endpoint and set ctx->dev to its device, which is the tunnel itself when that route resolves back to the tunnel. dev_fill_forward_path() then makes no progress and trips WARN_ON_ONCE(last_dev == ctx->dev) as soon as a flowtable tries to offload a flow through the tunnel. That routing loop is a configuration any CAP_NET_ADMIN user can set up, and ip_tunnel_xmit() and ip6_tnl_xmit() already treat it as a tx error, so remove the warning and just fail the walk, as commit 008e7a7c293b ("net: remove WARN_ON_ONCE when accessing forward path array") did for the path stack overflow. Fixes: ab427db17885 ("netfilter: flowtable: Add IPIP rx sw acceleration") Fixes: d98103575dcd ("netfilter: flowtable: Add IP6IP6 rx sw acceleration") Closes: https://lore.kernel.org/all/CA+0ovCgaRvbd0Udj70b2xxG8Cx3CaCpNhnf1V4RWQuDveZYZhA@mail.gmail.com/ Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Farhad Alemi <farhad.alemi@berkeley.edu> Reviewed-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn> Link: https://patch.msgid.link/CA+0ovCgKDOk+Bg6Gh5Lwx94u_jJjQ30-vY1JcY2BYfhnWJJbPA@mail.gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-15drop_monitor: fix out-of-bounds write in reset_per_cpu_data()Eric Dumazet1-2/+1
In reset_per_cpu_data(), al is computed as: al = sizeof(struct net_dm_alert_msg); al += dm_hit_limit * sizeof(struct net_dm_drop_point); al += sizeof(struct nlattr); skb = genlmsg_new(al, GFP_KERNEL); ... nla = nla_reserve(skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg)); ... msg = nla_data(nla); memset(msg, 0, al); Because al includes sizeof(struct nlattr) (the 4-byte attribute header), genlmsg_new() allocates al bytes of tailroom starting at nla. However, msg points to nla_data(nla), which is located sizeof(struct nlattr) bytes past nla. Calling memset(msg, 0, al) therefore writes al bytes starting from msg, exceeding the allocated buffer by sizeof(struct nlattr) (4 bytes) and corrupting skb_shared_info. Fix this by letting al represent only the payload length, allocating the skb with genlmsg_new(nla_total_size(al), GFP_KERNEL), and zeroing al bytes from msg. Fixes: 683703a26e46 ("drop_monitor: Update netlink protocol to include netlink attribute header in alert message") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn> Link: https://patch.msgid.link/20260910204612.3762015-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-15drop_monitor: use raw_cpu_ptr() in tracepoint probesEric Dumazet1-3/+3
syzbot reported a preemption warning in sk_skb_reason_drop(): BUG: using smp_processor_id() in preemptible [00000000] code: syz.0.17/5917 caller is net_dm_packet_trace_kfree_skb_hit+0x119/0x350 net/core/drop_monitor.c:519 In net_dm_packet_trace_kfree_skb_hit(), data = this_cpu_ptr(&dm_cpu_data) is evaluated before spin_lock_irqsave(&data->drop_queue.lock, flags). When kfree_skb() is called from preemptible context (e.g. process context during close() on /dev/net/tun), preemption is enabled, triggering the CONFIG_DEBUG_PREEMPT warning in smp_processor_id(). The same pattern exists in net_dm_hw_trap_summary_probe() and net_dm_hw_trap_packet_probe() for dm_hw_cpu_data. This is a false positive because each per-cpu structure is protected by its own spinlock. If the task migrates to another CPU right after reading the per-cpu pointer, the lock still safely synchronizes access to that queue. Use raw_cpu_ptr() instead of this_cpu_ptr() to silence CONFIG_DEBUG_PREEMPT without disturbing interrupt state or breaking PREEMPT_RT locking semantics. Fixes: ca30707dee2b ("drop_monitor: Add packet alert mode") Fixes: 5855357cd40e ("drop_monitor: Prepare probe functions for devlink tracepoint") Reported-by: syzbot+dc57fd6722deb17e92af@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6aa316b2.f81106d8.2ab401.0014.GAE@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260910204612.3762015-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-15drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardownEric Dumazet1-4/+4
In drop_monitor teardown paths (net_dm_trace_off_set(), net_dm_hw_monitor_stop(), and error unwind paths in net_dm_trace_on_set() and net_dm_hw_monitor_start()), per-CPU timers are stopped using timer_delete_sync() followed by cancel_work_sync(). However, there is a circular dependency between send_timer and dm_alert_work: 1) sched_send_work() (timer callback) schedules dm_alert_work. 2) send_dm_alert() / net_dm_hw_summary_work() calls reset_per_cpu_data() or net_dm_hw_reset_per_cpu_data(). 3) If memory allocation fails under memory pressure in the reset function, it re-arms the timer via mod_timer(&data->send_timer, ...). If dm_alert_work is running concurrently while timer_delete_sync() executes on another CPU, an allocation failure in the worker will re-arm the timer after timer_delete_sync() has already returned. Once cancel_work_sync() completes and module_put() is called, the timer remains active in the timer wheel. If the module is then unloaded, the timer will fire and execute sched_send_work() in freed memory, triggering a kernel panic / use-after-free. Switch from timer_delete_sync() to timer_shutdown_sync(). This guarantees that any in-flight timer handler has finished and prevents subsequent re-arming attempts from running workers from succeeding. When monitoring is restarted later, timer_setup() is invoked, which cleanly re-initializes the timer. Fixes: 9398e9c0b1d4 ("drop_monitor: Perform cleanup upon probe registration failure") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260910204612.3762015-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-15drop_monitor: synchronize tracepoint unregistration on error pathEric Dumazet1-0/+1
If register_trace_napi_poll() fails in net_dm_trace_on_set(), unregister_trace_kfree_skb() is called to roll back the kfree_skb tracepoint registration. However, tracepoint_synchronize_unregister() is omitted before calling cancel_work_sync() and module_put(). An in-flight probe executing concurrently on another CPU could call schedule_work() after cancel_work_sync() has already returned, leaving a pending work item scheduled after the module reference is dropped. If the module is then unloaded, executing the work item triggers a kernel panic. Add tracepoint_synchronize_unregister() after unregister_trace_kfree_skb() in the error path, matching net_dm_trace_off_set() and net_dm_hw_probe_unregister(). Fixes: 7c747838a558 ("drop_monitor: Split tracing enable / disable to different functions") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Hangbin Liu <liuhangbin@kylinos.cn> Link: https://patch.msgid.link/20260910204612.3762015-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-13bpf, sockmap: Fix self-redirect copied_seq double-countingGeliang Tang1-0/+4
When a BPF stream_verdict program redirects an skb back to the same socket (self-redirect with BPF_F_INGRESS), sk_psock_verdict_apply() calls tcp_eat_skb() which advances tcp_sk->copied_seq. However, the skb is then delivered to the socket's psock ingress queue and later read by tcp_bpf_recvmsg_parser(), which also advances copied_seq via the copied_from_self accounting path. This double-counting causes copied_seq to advance by 2x the actual data length, triggering: TCP recvmsg seq # bug 2: copied BF2E806, seq BF2E7FD, \ rcvnxt BF2E806, fl 0 WARNING: net/ipv4/tcp.c:2745 at tcp_recvmsg_locked+0x72b/0x2640 Call Trace: tcp_recvmsg+0x10a/0x500 sock_recvmsg+0x168/0x1d0 __sys_recvfrom+0x19a/0x2a0 __x64_sys_recvfrom+0xe4/0x1f0 do_syscall_64+0xf7/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f cleanup rbuf bug: copied BF2E806 seq BF2E806 rcvnxt BF2E806 WARNING: net/ipv4/tcp.c:1609 at tcp_cleanup_rbuf+0xf2/0x1c0 Call Trace: tcp_recvmsg_locked+0x8d1/0x2640 tcp_recvmsg+0x10a/0x500 sock_recvmsg+0x168/0x1d0 __sys_recvfrom+0x19a/0x2a0 __x64_sys_recvfrom+0xe4/0x1f0 do_syscall_64+0xf7/0x530 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fix this by converting self-redirect verdict to __SK_PASS at the beginning of sk_psock_verdict_apply(). This bypasses the __SK_REDIRECT case entirely (which calls sk_psock_eat_skb), letting the __SK_PASS path queue the skb to the psock ingress queue. The data is then read via tcp_bpf_recvmsg_parser(), which advances copied_seq exactly once through copied_from_self. Cross-socket redirects continue through __SK_REDIRECT with sk_psock_eat_skb() unchanged. Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Suggested-by: Jiayuan Chen <jiayuan.chen@linux.dev> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://lore.kernel.org/r/1a8e797a1b26e2f695aaac22ac644c2862f63466.1788858299.git.tanggeliang@kylinos.cn Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-12bpf: Fix out-of-bounds read of rtt_min in sock_opsJiayuan Chen1-12/+1
A sockops prog reading skops->rtt_min never checks the sk type: on the tcp_conn_request() path sock_ops->sk is a request_sock (non-full), and the ctx rewrite casts it to a tcp_sock (full) and reads rtt_min past the end of the request_sock, returning dirty adjacent memory. SEC("sockops") int prog(struct bpf_sock_ops *skops) { switch (skops->op) { case BPF_SOCK_OPS_RWND_INIT: leak = skops->rtt_min; /* reads the request_sock OOB */ ... } } For instance one such read returned rtt_min=0xffff8881, the high half of a leaked kernel pointer. Guarding that cast is exactly what SOCK_OPS_GET_FIELD() does -- it checks is_locked_tcp_sock and returns 0 when sock_ops->sk is not a locked full socket. Every other tcp_sock field in sock_ops goes through it; rtt_min is the only one open-coded, so it skips the check. Read rtt_min through SOCK_OPS_GET_FIELD() too. rtt_min is a bit special: it is a struct minmax and we only want the current min, so pass rtt_min.s[0].v. That is equivalent to the old hand-computed offset offsetof(struct tcp_sock, rtt_min) + sizeof_field(struct minmax_sample, t) (s[0] sits at rtt_min + 0 and .v at + sizeof(.t), i.e. what minmax_get() returns), so the loaded field is unchanged and only the full-sock guard is added. The two BUILD_BUG_ON()s that protected the hand-computed offset are no longer needed. Before patch: 0: r1 = *(u64 *)(r1 +0) ; r1 = skops->sk 1: r1 = *(u32 *)(r1 +2324) ; ((tcp_sock *)sk)->rtt_min.s[0].v After patch: 0: *(u64 *)(r1 +56) = r9 1: r9 = *(u8 *)(r1 +50) ; is_locked_tcp_sock 2: if r9 == 0 goto pc+4 ; not a locked full sock -> 0 3: r9 = *(u64 *)(r1 +56) 4: r1 = *(u64 *)(r1 +0) ; r1 = skops->sk 5: r1 = *(u32 *)(r1 +2324) ; rtt_min.s[0].v 6: goto pc+2 7: r9 = *(u64 *)(r1 +56) 8: r1 = 0 Fixes: 44f0e43037d3 ("bpf: Add support for reading sk_state and more") Reported-by: VEGA <vega@nebusec.ai> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Link: https://lore.kernel.org/r/20260903100921.113374-1-jiayuan.chen@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-11neighbour: Skip default parms when resumed in neightbl_dump_info().Kuniyuki Iwashima1-3/+8
neightbl_dump_info() calls neightbl_fill_info() in each loop to render the default parms. If there are many devices and neightbl_fill_param_info() failed, neightbl_fill_info() is called again when the dump resumes: # ynl --family rt-neigh --dump getneightbl --output-json | jq '.[] | {name: .name, ifindex: .parms.ifindex}' ... { "name": "ndisc_cache", "ifindex": null } ... { "name": "ndisc_cache", "ifindex": 6 } { "name": "ndisc_cache", "ifindex": null } { "name": "ndisc_cache", "ifindex": 5 } Let's skip neightbl_fill_info() if it is already called in neightbl_dump_info(). Note that we cannot use !neigh_skip instead of !default_skip because default_skip == 1 && neigh_skip == 0 could be true if the first neightbl_fill_param_info() fails. Also, nidx must be cleared at the end of each table loop; otherwise, if neightbl_fill_info() for a subsequent table fails, the leftover nidx from the previous table would be saved in cb->args[1], resulting in erroneously skipping parms of the subsequent table in the next dump. Fixes: c7fb64db001f ("[NETLINK]: Neighbour table configuration and statistics via rtnetlink") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260909233143.2401847-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-11neighbour: Don't render blackhole_netdev via RTM_GETNEIGHTBL.Kuniyuki Iwashima1-1/+1
The cited commits started to initialise blackhole_netdev with neigh_parms_alloc(). This is visible in init_net as the ifindex==0 entries via RTM_GETNEIGHTBL: # ynl --family rt-neigh --dump getneightbl --output-json \ | jq '.[] | select(.parms.ifindex == 0) | {name: .name, ifindex: .parms.ifindex}' { "name": "arp_cache", "ifindex": 0 } { "name": "ndisc_cache", "ifindex": 0 } For RTM_SETNEIGHTBL, ifindex being 0 means wildcard. Let's skip blackhole_netdev's parms in neightbl_dump_info(). Note that lookup_neigh_parms() does not need the same change because the default parms is always the first entry and matches with ifindex == 0. Fixes: e5f80fcf869a ("ipv6: give an IPv6 dev to blackhole_netdev") Fixes: 22600596b675 ("ipv4: give an IPv4 dev to blackhole_netdev") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260909233143.2401847-4-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-11neighbour: Enforce min/max to NDTPA_INTERVAL_PROBE_TIME_MS.Kuniyuki Iwashima1-4/+13
NDTPA_INTERVAL_PROBE_TIME_MS sets .type and .min but misses .validation_type, so no validation is applied: # ynl --family rt-neigh --do setneightbl \ --json '{"name": "arp_cache", "parms": {"interval-probe-time-ms": 0}}' # ynl --family rt-neigh --dump getneightbl --output-json | \ jq '.[] | select(.name == "arp_cache" and has("config")) | .parms["interval-probe-time-ms"]' 0 Moreover, nla_get_msecs() uses msecs_to_jiffies(), and u64 is silently cast to u32, so a larger value can bypass the min check: e.g. 4294967296 == 0x100000000 # ynl --family rt-neigh --do setneightbl \ --json '{"name": "arp_cache", "parms": {"interval-probe-time-ms": 4294967296}}' # ynl --family rt-neigh --dump getneightbl --output-json | \ jq '.[] | select(.name == "arp_cache" and has("config")) | .parms["interval-probe-time-ms"]' 0 msecs_to_jiffies() returns MAX_JIFFY_OFFSET if the value is larger than INT_MAX. Also, INT_MAX ms overflows int NEIGH_VAR() when HZ > 1000 (Alpha, MIPS), and passing a negative integer to queue_delayed_work(unsigned long delay) causes sign extension, which wraps around the expiry time to the past, resulting in it being handled as 0 delay in the timer wheel. Let's use NLA_POLICY_FULL_RANGE() and limit the max to 1 day. The same max check is applied to sysctl as well. Note that this controls the probe interval for NTF_MANAGED entries, so the max of 1 day is unlikely to break any deployments. Fixes: 211da42eaa45 ("net, neigh: introduce interval_probe_time_ms for periodic probe") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260909233143.2401847-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-11neighbour: Add missing RCU annotation for neightbl_dump_info().Kuniyuki Iwashima1-2/+5
neightbl_dump_info() fetches the first non-default neigh_parms with list_next_entry(&tbl->parms, ...) and iterates through the list with list_for_each_entry_from_rcu(). However, list_next_entry() does not use RCU helper. Let's use list_for_each_entry_rcu() and skip the default parms. Fixes: 4ae34be50064 ("neighbour: Convert RTM_GETNEIGHTBL to RCU.") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260909233143.2401847-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-10bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destroy()Jiayuan Chen1-4/+9
sk_protocol lives in struct sock, not in struct sock_common. A timewait or request sock handed to bpf_sock_destroy() by the tcp iterator is neither, so reading sk->sk_protocol runs past the object: ================================================================== BUG: KASAN: slab-out-of-bounds in bpf_sock_destroy+0xc7/0xe0 Read of size 2 at addr ffff8881047d11b4 by task test_progs/428 Tainted: [W]=WARN Call Trace: <TASK> dump_stack_lvl+0x91/0xf0 print_report+0xd1/0x630 kasan_report+0xf3/0x130 __asan_report_load2_noabort+0x14/0x30 bpf_sock_destroy+0xc7/0xe0 bpf_prog_c3dd61f9d9cd9f37_iter_tcp6_timewait+0x9f/0xb7 bpf_iter_run_prog+0x538/0xde0 bpf_iter_tcp_seq_show+0x26b/0x4b0 bpf_seq_read+0x424/0x1210 vfs_read+0x197/0xe40 ksys_read+0x119/0x240 __x64_sys_read+0x72/0xc0 x64_sys_call+0x647/0x27e0 do_syscall_64+0xe5/0x610 entry_SYSCALL_64_after_hwframe+0x76/0x7e Only check sk_protocol on full socks. tcp_abort() already knows how to deal with TIME_WAIT and NEW_SYN_RECV socks. Also fix the comment, it never matched the code. Fixes: 4ddbcb886268 ("bpf: Add bpf_sock_destroy kfunc") Reported-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Closes: https://lore.kernel.org/bpf/20260702224519.800135-1-xmei5@asu.edu/ Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://lore.kernel.org/r/20260910112634.152195-1-jiayuan.chen@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-09bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCALWeiming Shi1-0/+2
An LWT_SEG6LOCAL program can invalidate its cached SRH with bpf_lwt_seg6_adjust_srh() and then call bpf_skb_pull_data(). The latter may reallocate skb->head, leaving the per-CPU SRH pointer dangling. Post-program SRH validation then writes through that pointer. Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL programs so the verifier rejects this unsafe helper combination. Other LWT program types continue to expose the helper through lwt_out_func_proto(). Fixes: 004d4b274e2a ("ipv6: sr: Add seg6local action End.BPF") Reported-by: co+adfca3e91be95776@bugs.sh Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Closes: https://lore.kernel.org/all/GCy0KRM2IcQGoJQTjJEU9D0maBxXzEDHuQpq@bugs.sh/ Link: https://lore.kernel.org/bpf/DL9COXZQXX4V.1FN45QO2Q77ZH@gmail.com/ Link: https://lore.kernel.org/bpf/20260909040807.3885815-2-bestswngs@gmail.com
2026-09-07bpf: Fix bpf_skb_change_tail wrt csum partial skbsDaniel Borkmann1-6/+5
Cilium generates ICMP "frag needed" replies from BPF when a LB DSR packet exceeds the egress MTU. The reply is built by first trimming the packet down to target size via bpf_skb_change_tail(), and then pushing the ICMP error headers in front of it. The trim is rejected for skbs which carry a checksum offload, e.g. TCP packets aggregated by GRO on ingress where tcp_gro_complete() leaves the skb as CHECKSUM_PARTIAL. __bpf_skb_min_len() raises the minimum length to the end of the L4 checksum field, so a trim to 42 bytes bails out with -EINVAL given a min_len of 52 in this case, and due to that the ICMP generator fails. This is not the case if GRO is turned off. Fix this bpf_skb_change_tail() restriction and drop the checksum offload when the new length no longer covers the checksum field. The BPF program rewrites the skb into an ICMP error and computes the checksum itself anyway. Fixes: 5293efe62df8 ("bpf: add bpf_skb_change_tail helper") Reported-by: Tom Hadlaw <tom.hadlaw@isovalent.com> Reported-by: Yusuke Suzuki <yusuke.suzuki@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20260907121025.1923656-1-daniel@iogearbox.net Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-09-04net: reject oversized tx_queue_len at netlink parse timeJamal Hadi Salim1-1/+6
rtnl_create_link() assigns IFLA_TXQLEN directly to dev->tx_queue_len without going through netif_change_tx_queue_len(), so a device created with "ip link add ... txqueuelen 500000" bypasses the S16_MAX cap and still triggers the oversized ring allocations in pfifo_fast, tun and tap. The veth peer nest (rtnl_nla_parse_ifinfomsg()) and the RTM_NEWLINK-on-existing-device path reach the same sinks. Enforce the cap in ifla_policy instead: IFLA_TXQLEN becomes NLA_POLICY_FULL_RANGE(NLA_U32, &txqlen_range) with txqlen_range = { .min = 0, .max = S16_MAX }. All netlink consumers parse against this policy - rtnl_setlink(), rtnl_newlink() (create and change), and the veth peer nest - so every netlink path is capped at parse time and rejects the attribute with -ERANGE plus a proper "integer out of range" extack message before any device state is modified (the RTM_SETLINK half-application wart is gone with it). Document the bound in the rt-link.yaml netlink spec. Conditions to recreate the bug: - CONFIG_NET_SCHED=y, CONFIG_VETH=y, CONFIG_USER_NS=y, CONFIG_NET_NS=y. - Unprivileged user in a fresh user+net namespace (unshare -Urn): ip link add v0 txqueuelen 500000 type veth peer name v1 -> on the fixed kernel this is rejected with -ERANGE ("integer out of range" extack) instead of installing an oversized tx_queue_len that later inflates pfifo_fast/tun/tap ring allocations. - ip link set v0 txqueuelen 500000 is likewise rejected at parse time. Fixes: 38f7b870d4a6 ("[RTNETLINK]: Link creation API") Reported-by: Vega <vega@nebusec.ai> Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/QDISC-2899.v2.20260901233641@mojatatu.com.2 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-04net: cap tx_queue_len at S16_MAX to prevent oversized ring allocationsJamal Hadi Salim1-1/+1
Several subsystems allocate ring buffers sized by dev->tx_queue_len with no upper bound. An unprivileged user (via unshare -Urn) can set a huge tx_queue_len and exhaust global memory with ring allocations: - pfifo_fast: pfifo_fast_init() and pfifo_fast_change_tx_queue_len() allocate 3 skb_array rings of tx_queue_len entries each. - tun: tun_queue_resize() and the queue-attach path resize ptr_rings to tx_queue_len on the NETDEV_CHANGE_TX_QUEUE_LEN notifier. - tap (macvtap/ipvtap): tap_queue_resize() and tap_init() resize/init ptr_rings to tx_queue_len on the same notifier. netif_change_tx_queue_len() is the single entry point for IFLA_TXQLEN, sysfs, and the SIOCSIFTXQLEN ioctl. Cap new_len at S16_MAX (32767) there so the oversized value is rejected at set time. This takes effect whether the device is up or down, before dev->tx_queue_len is written, before any notifier fires, and before any ring is allocated. The "> S16_MAX" check also subsumes the previous unsigned-long truncation test, and a negative ifr_qlen from the ioctl lands far above the cap after conversion, so both old failure modes are covered by the one comparison. tx_queue_len is ambigious: both a per-ring sizing multiplier and a default queue-length/limit knob for consumers that allocate nothing at set time (pfifo/bfifo/gred/plug/sfb limits, htb direct_qlen, qfq max_classes, teql). 32767 is chosen as the largest value NLA_POLICY_FULL_RANGE can express for the u32 IFLA_TXQLEN policy in patch 2/3 while staying a legitimate queue length on high-BDP paths; the ring-memory trade-off of a shared knob is disclosed below. Conditions to recreate the bug: - CONFIG_NET_SCHED=y, CONFIG_VETH=y, CONFIG_USER_NS=y, CONFIG_NET_NS=y. - Unprivileged user in a fresh user+net namespace (unshare -Urn). - pfifo_fast: create veth pairs, set tx_queue_len to 500000, attach mq+pfifo_fast. ~28 iterations OOMs a 2GB guest. - tun: create 50 tun devices with IFF_MULTI_QUEUE, set tx_queue_len to 500000, open 8 queues each. ~1.6GB of ptr_ring allocations OOMs a 512MB guest. - tap: same as tun with IFF_TAP. ~960MB OOMs a 512MB guest. - On the fixed kernel the oversized tx_queue_len is rejected with -ERANGE at set time (all four paths: RTM_SETLINK, RTM_NEWLINK create, sysfs, ioctl - the latter two via this check, the former two via this check and the 2/3 parse policy respectively). Fixes: 6a643ddb5624 ("net: introduce helper dev_change_tx_queue_len()") Reported-by: Vega <vega@nebusec.ai> Closes: https://lore.kernel.org/netdev/20260828121902.66837-1-jhs@mojatatu.com/ Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/QDISC-2899.v2.20260901233641@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-04net: mpls: clear inner_protocol when the last label is poppedFourie Zhang1-0/+7
skb_mpls_push() records the pre-encapsulation network header once, gated on !skb->inner_protocol. skb_mpls_pop() never clears that record, so it outlives the encapsulation it describes. Open vSwitch can then re-push MPLS onto a packet whose inner_network_header still points at the older, deeper offset: push a label, pop every label, recirculate (ovs_flow_key_update() re-derives key->eth.type and resets network_header, but leaves inner_*), then push again. ovs_fragment() trusts the record: skb->network_header = skb->inner_network_header; so skb_network_offset() goes negative. The bound check is signed: if (skb_network_offset(skb) > MAX_L2_LEN) a negative offset passes it, and prepare_frag() widens the value: unsigned int hlen = skb_network_offset(skb); memcpy(&data->l2_data, skb->data, hlen); which is a ~4GiB memcpy out of a 30-byte per-CPU buffer. Reproduced on v7.3-rc1. RDX is the truncated length, (unsigned int)(-8): BUG: unable to handle page fault for address: ffffe8ffffc16000 #PF: supervisor write access in kernel mode Oops: 0002 [#1] SMP KASAN NOPTI RIP: 0010:memcpy+0x8/0x20 RDX: 00000000fffffff8 RSI: ffff888105d732db RDI: ffffe8ffffc16000 prepare_frag+0x3df/0x4e0 ovs_fragment+0x589/0x7e0 do_output+0x4ce/0x5e0 do_execute_actions+0x55d2/0x7b30 ovs_execute_actions+0xea/0x450 Same root-cause shape as commit 975b5b067f52 ("ipv6: sr: restore network header before routing and forwarding"): a stale network header offset reaching a consumer that widens it. Here it originates in the MPLS push/pop path. Clear inner_protocol once the packet is no longer MPLS, so a later push re-records the current header. net/sched/act_mpls.c is the only other skb_mpls_pop() caller and gets the same fix; sch_frag.c saves and restores inner_protocol around fragmentation in the same way OVS does. Fixes: 48d2ab609b6b ("net: mpls: Fixups for GSO") Cc: stable@vger.kernel.org Signed-off-by: Fourie Zhang <fouriezhang@tencent.com> Acked-by: Jiri Benc <jbenc@redhat.com> Link: https://patch.msgid.link/20260902092719.2874481-1-fouriezhang@tencent.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-02net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().Kuniyuki Iwashima1-12/+13
syzbot reported the warning in cfg80211_pernet_exit(). [0] The repro does the following: 1. create two device in root netns and non-root netns 2. assign the same altname for the two devices 3. remove the non-root netns Since commit 7663d522099e ("net: check for altname conflicts when changing netdev's netns"), cfg80211_switch_netns() and cfg802154_switch_netns() fail if init_net has a device with the conflicting altname. default_device_exit_net() had the same issue and commit d09486a04f5d ("net: fix removing a namespace with conflicting altnames") fixed it. cfg80211_pernet_exit() and cfg802154_pernet_exit() need the same fix. Let's generalise the fix by removing conflicting altnames for dying netns in __dev_change_net_namespace(). [0]: cfg80211_switch_netns(rdev, &init_net) WARNING: net/wireless/core.c:1871 at cfg80211_pernet_exit+0xd5/0x120 net/wireless/core.c:1871, CPU#1: kworker/u8:9/1160 Modules linked in: CPU: 1 UID: 0 PID: 1160 Comm: kworker/u8:9 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: netns cleanup_net RIP: 0010:cfg80211_pernet_exit+0xd5/0x120 net/wireless/core.c:1871 Code: e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 b4 ef 0e f7 4d 8b 36 49 81 fe 20 10 4a 90 74 12 e8 03 3d 9f f6 eb 85 e8 fc 3c 9f f6 90 <0f> 0b 90 eb cc e8 f1 3c 9f f6 eb 05 e8 ea 3c 9f f6 5b 41 5c 41 5e RSP: 0018:ffffc900057a78f0 EFLAGS: 00010293 RAX: ffffffff8b287154 RBX: ffff88807ba72780 RCX: ffff8880213e8000 RDX: 0000000000000000 RSI: 00000000ffffffef RDI: 0000000000000000 RBP: 00000000ffffffef R08: ffffffff9024cc67 R09: 0000000000000000 R10: fffff52000af4eb0 R11: fffffbfff204998d R12: dffffc0000000000 R13: ffffffff904a1080 R14: ffff888144ed0008 R15: ffff888144ed0e20 FS: 0000000000000000(0000) GS:ffff888124de6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005642de0a8a70 CR3: 000000007a40c000 CR4: 00000000003526f0 Call Trace: <TASK> ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x43d/0x8d0 net/core/net_namespace.c:253 cleanup_net+0x572/0x810 net/core/net_namespace.c:706 process_one_work kernel/workqueue.c:3387 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames") Reported-by: syzbot+74f338e09f1ef3ee6457@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6a96219e.04428c52.29b18.0001.GAE@google.com/T/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260901005550.2042357-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-01net: psp: do not inherit the Rx association on cloneNorbert Szetei1-0/+3
sk->psp_assoc sits past sk_dontcopy_end, so sock_copy() copies it into every socket accepted from a listener without taking a reference, while inet_sock_destruct() puts for every inet socket. psp_twsk_init() does refcount_inc() for the timewait socket, so a child closing through TIME_WAIT cancels its own put and leaves the association with one reference and N timewait sockets holding the same pointer. Closing the listener frees it, and the timewait timers then put freed memory. Rejecting the association on a listening socket is not sufficient: a socket can acquire one while established and then be turned back into a listener, because tcp_disconnect() leaves sk->psp_assoc in place. BUG: KASAN: slab-use-after-free in psp_twsk_assoc_free+0x6f/0xf0 Write of size 4 at addr ffff888110f9255c by task swapper/7/0 psp_twsk_assoc_free+0x6f/0xf0 inet_twsk_put+0xda/0x1b0 call_timer_fn+0x53/0x2e0 __run_timers+0x764/0xa80 Freed by task 99: kfree+0x1a7/0x500 process_one_work+0x7ec/0x1100 An association carries a per-connection SPI and key, so a child must not inherit the parent's. Clear it on clone. Fixes: 6b46ca260e22 ("net: psp: add socket security association code") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-5 Signed-off-by: Norbert Szetei <norbert@doyensec.com> Reviewed-by: Daniel Zahka <daniel.zahka@gmail.com> Link: https://patch.msgid.link/BC10EB92-ABB3-41B2-AB16-266BEEBE18C0@doyensec.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-31page_pool: keep frag_offset aligned for odd-sized requestsFlorian Schauer1-1/+2
page_pool_alloc_frag_netmem() rounds the requested fragment size with size = ALIGN(size, dma_get_cache_alignment()); dma_get_cache_alignment() returns 1 unless the architecture defines ARCH_DMA_MINALIGN, which DMA-coherent architectures such as x86 do not. There the ALIGN() is a no-op and pool->frag_offset advances by the raw, unrounded size. A single caller asking for an odd size then leaves frag_offset misaligned for every fragment carved out of that page afterwards. The pool is shared, so the damage is not confined to the caller that caused it. The per-cpu system_page_pool used by generic XDP hits this. skb_pp_cow_data() allocates its fragments with the raw packet length: size = min_t(u32, len, PAGE_SIZE); truesize = size; page = page_pool_dev_alloc(pool, &page_off, &truesize); leaving frag_offset odd for whatever is carved out of that page next. Its own head allocation is already aligned -- SKB_HEAD_ALIGN(size) plus the XDP_PACKET_HEADROOM its callers pass -- so it is a later user of the shared pool that pays: page_pool_dev_alloc_va() returns a misaligned buffer, napi_build_skb() installs it as skb->head, and skb_shinfo(skb) == skb->head + skb->end is misaligned with it. skb_shinfo()->dataref is a 4-byte atomic_t at offset 0x20, so the atomic_inc() in __skb_clone() straddles a cache line. On x86 with split lock detection -- fatal for kernel split locks by default -- this panics the machine: Oops: Split lock detected RIP: 0010:skb_clone+0x154/0x1e0 Call Trace: <IRQ> raw_local_deliver+0x1ed/0x2c0 ip_protocol_deliver_rcu+0x54/0x1c0 ip_local_deliver_finish+0x85/0x100 ip_local_deliver+0x67/0x100 __netif_receive_skb_one_core+0x85/0xa0 process_backlog+0x87/0x130 Reproduced by attaching any generic-mode XDP program to loopback and opening a RAW IPPROTO_UDP socket, which makes raw_local_deliver() clone every locally delivered UDP packet; ordinary DNS traffic then triggers it, roughly once per 2500 clones. Observed on 6.12.101 and 7.1.8. Tracing page_pool_alloc_frag_netmem() over one such run shows the amplification -- two odd-sized requests, nine misaligned offsets: requested size & 7: 0: 17035 5: 1 7: 1 frag_offset & 7: 0: 17028 3: 1 4: 1 5: 1 6: 1 7: 5 and skb_pp_cow_data() returning heads that were aligned on entry: head 0xffff8f4c86aeac00 -> 0xffff8f4c53a9a9c4 (&7=4) head 0xffff8f4d6a8a42c0 -> 0xffff8f4c4f7b7a45 (&7=5) Round the fragment size up to at least the alignment struct skb_shared_info requires, so fragments are always suitably aligned for the objects callers build on them. Architectures needing a larger DMA alignment keep it. This also makes the remainder computed in page_pool_alloc_netmem(), *size = max_size - *offset; aligned, since max_size is a power of two -- which fixes the matching misalignment of skb->end. Verified with a controlled A/B under QEMU/KVM: same tree, same config, same compiler, same rootfs and identical traffic, differing only by this patch. A SEC("xdp.frags") XDP_PASS program on lo plus UDP datagrams larger than max_head_size drives skb_pp_cow_data()'s fragment loop, which passes raw packet lengths to the pool. Measured at the return of skb_pp_cow_data(): unpatched patched skb_pp_cow_data calls 40800 40800 misaligned skb->head 1120 0 dataref at line offset >60 80 0 The last row counts the accesses that actually fault: skb_shinfo()->dataref sits at head+end+0x20 and is a 4-byte atomic, so `lock incl` splits a 64-byte cache line only when that address lands at offset 61..63. All 80 occurrences were at offset 61; the panic reported above was at offset 62. Eliminating the misalignment removes every one of them. Same class of bug as commit 3bed3cc4156e ("net: Do not allocate page fragments that are not skb aligned"), which fixed the older netdev_alloc_frag()/napi_alloc_frag() allocators. Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool") Cc: stable@vger.kernel.org Signed-off-by: Florian Schauer <florian@schauer.to> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260828060822.2628276-1-florian@schauer.to Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-28net: iptunnel: fix stale transport header during tunnel decapsulationDong Chenchen1-0/+2
Syzbot reported a crash in qdisc_pkt_len_segs_init() caused by a stale transport_header offset after tunnel decapsulation. BUG: unable to handle page fault for address: ffffed102091a42e Oops: Oops: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 340 Comm: qdisc_uaf_repro Not tainted 7.2.0-rc4-00061-g248951ddc14d #256 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__asan_load2 <IRQ> qdisc_pkt_len_segs_init (net/core/dev.c:4145) __dev_queue_xmit (net/core/dev.c:4787) br_dev_queue_push_xmit (net/bridge/br_forward.c:53) br_handle_frame_finish (net/bridge/br_input.c:229) br_handle_frame (net/bridge/br_input.c:315) __netif_receive_skb_core.constprop.0 (net/core/dev.c:6099) __netif_receive_skb_list_core (net/core/dev.c:6287) netif_receive_skb_list_internal (net/core/dev.c:6445) napi_complete_done (net/core/dev.c:6813) gro_cell_poll (net/core/gro_cells.c:74) __napi_poll (net/core/dev.c:7735) net_rx_action (net/core/dev.c:7798 net/core/dev.c:7955) handle_softirqs (kernel/softirq.c:622) do_softirq (kernel/softirq.c:523 kernel/softirq.c:510 ) __local_bh_enable_ip (kernel/softirq.c:450) tun_get_user (drivers/net/tun.c:1986 (discriminator 1)) tun_chr_write_iter (drivers/net/tun.c:2032) The issue is completely latent until qdisc read transport header in commit 7fb4c1967011 ("net: pull headers in qdisc_pkt_len_segs_init()"). The crash requires four conditions to line up: 1. The incoming packet is encapsulated and carries GSO metadata. The outer transport header offset is stored in skb->transport_header while the packet is still in the outer tunnel context. 2. The tunnel receiver strips the outer headers. skb->data is advanced to the inner frame, but skb->transport_header is left pointing to the now-removed outer L4 header, so it becomes a negative offset relative to the new data. 3. The inner frame is not delivered to the local IP stack. Instead, it is forwarded at L2 by a bridge or HSR, so ip_rcv_core() never runs and the transport header is not reset to the inner L4 offset. 4. The forwarding path calls __dev_queue_xmit(), which enters qdisc_pkt_len_segs_init(). That function computes the GSO header length from skb_transport_offset(skb). Because the offset is negative, the unsigned cast overflows and pskb_may_pull(skb, hdr_len + sizeof(struct tcphdr)) reads past the end of the skb, triggering a KASAN fault or page fault. The issue specifically requires GSO packets (shinfo->gso_size != 0), which are processed/aggregated through gro_cells. Fix this by clearing transport_header to the ~0U sentinel in gro_cell for all tunnnel driver. GTP does not support GRO/GSO, drop the evil GSO packets in GTP directly. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+83181a31faf9455499c5@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69de2bee.a00a0220.475f0.0041.GAE@google.com/T/ Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260825123909.1463121-1-dongchenchen2@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-27net: Guard for gso_segs overflow in skb_segmentAlice Mikityanska1-1/+2
skb_segment calculates 32-bit partial_segs as len / gso_size, and then assigns it to the 16-bit gso_segs field. The division might overflow in some edge cases where the SKB is BIG TCP (65536 <= len <= 8*65535), and gso_size < TCP_MIN_GSO_SIZE = 8. While normally this can't happen due to TCP_MIN_GSO_SIZE, an AF_PACKET PACKET_VNET_HDR socket could generate such a malformed packet until the previous patch. Blocking malformed virtio_net packets was implemented in the previous patch, but this patch clamps partial_segs in skb_segment itself for more generic robustness. Should len / gso_size happen to be bigger than 65535 in partial GSO, skb_segment will now just produce more than two output SKBs, all of which will be valid with gso_segs <= 65535. In order to catch possible other cases of too many partial_segs, add a DEBUG_NET_WARN_ON_ONCE when len / gso_size happens to be too big. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Link: https://patch.msgid.link/20260822120117.1163423-3-alice.kernel@fastmail.im Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-25net: fix a resource leak in copy_net_ns() error handling pathTetsuo Handa1-12/+9
Currently, preinit_net() does two things: (1) call ns_common_init() which might fail (2) initialize resources which does not fail However, preinit_net() is returning early when (1) fails, and copy_net_ns() is jumping to the dec_ucounts: label. As a result, resources allocated by net_alloc() are leaking. We need to call key_remove_domain() and net_passive_dec() in order to release resources allocated by net_alloc(). We cannot simply jump to the put_userns: label when preinit_net() failed, for (2) is not yet done. But we can reorder (1) and (2), for there is no dependency between (1) and (2). Therefore, this patch decouples (1) from preinit_net() and changes preinit_net() back to a void function, and calls ns_common_init() after preinit_net() succeeded. Then, we can jump to immediately after ns_common_free() of the put_userns: label. Reported-by: sashiko (no mail address) Closes: https://sashiko.dev/#/patchset/af7dabf3-d0d7-46dc-a878-e1715b3c9ac6%40I-love.SAKURA.ne.jp Fixes: 08027f6b790b ("net: use ns_common_init()") Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://patch.msgid.link/c182cf90-1ed7-435b-88f7-9f00e88a0487@I-love.SAKURA.ne.jp Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-25net: core: fix head-page leak in skb_zerocopyMina Almasry1-2/+2
When skb_orphan_frags() throws -ENOMEM, skb_copy_ubufs() may have already reallocated and replaced 'from->head'. Accessing from->head to drop the old refcount leaks the original head page, and erroneously puts an unrelated new buffer. Use the local 'page' tracker variable instead to drop the reference properly. Fixes: 36d5fe6a0007 ("core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors") Signed-off-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20260823183602.1051453-2-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-25net: core: check skb_frags_readable before uncloning in skb_copy_ubufsMina Almasry1-3/+3
skb_copy_ubufs drops clones and modifies the SKB via pskb_expand_head() before checking for !skb_frags_readable(skb). This alters the SKB geometry prior to throwing an -EFAULT on an invalid SKB. Check readability first. Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags") Signed-off-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20260823183602.1051453-1-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-25net: skbuff: don't touch shared zerocopy state in skb_tx_error()Norbert Szetei1-1/+4
skb_tx_error() completes the zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, and skb_zcopy_downgrade_managed() clears SKBFL_MANAGED_FRAG_REFS. Both live in skb_shinfo(), which every clone shares, while the caller only owns the reference it is about to drop. Through a clone it tells the producer its pages are free and drops SKBFL_SHARED_FRAG for an skb that is still in flight. Open vSwitch reaches this with a non-last OVS_ACTION_ATTR_RECIRC: clone_execute() sends a skb_clone() into ovs_dp_process_packet() while do_execute_actions() keeps forwarding the original, and skb_clone() does not privatise the frags here -- skb_orphan_frags() returns early on SKBFL_DONT_ORPHAN. A flow miss on the clone then strips the marker from the packet still being forwarded, and a later local ESP delivery decrypts in place over frags it does not own privately. Skip it for a cloned skb. Nothing is lost: skb_release_data() clears the zerocopy state once the last reference to the shared data goes. Fixes: 25121173f7b1 ("skb: api to report errors for zero copy skbs") Cc: stable@vger.kernel.org Suggested-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Norbert Szetei <norbert@doyensec.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Tested-by: Jongmin Jang <payload.jang@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/CFAB292A-674B-4C14-BB2C-BB8830AD5659@doyensec.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-25net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()Norbert Szetei1-1/+0
skb_zerocopy() copies frags from @from into @to. On an skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive operation on the source skb the copy helper does not own. That completes @from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the SKBFL_SHARED_FRAG page-ownership marker. Both callers already report the failure on their own drop path. nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost by dropping it here. On Open vSwitch's OVS_ACTION_ATTR_USERSPACE path the skb is not freed on this error: do_execute_actions() ignores output_userspace()'s return value and, unless the upcall was the last action, keeps forwarding the same skb through the flow's remaining actions. The uarg is completed while that skb is still in flight, telling the producer its buffers are free, and SKBFL_SHARED_FRAG is cleared on an skb the rest of the stack still handles. That flag is what makes esp_input() call skb_cow_data() instead of decrypting in place, so a later local ESP delivery can decrypt over frags the skb does not own privately. Leave error reporting to the callers. Fixes: 36d5fe6a0007 ("core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors") Cc: stable@vger.kernel.org Suggested-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Norbert Szetei <norbert@doyensec.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/6E3A780D-FB87-421F-9964-B1D457D7D106@doyensec.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-22net: page_pool: Remove zone/policy GFP flags when allocating XArray entriesRong Zhang1-0/+7
Net drivers request GFP flags according to both the current context and the device constraints, but the XArray entry itself is by no mean used by the device. Passing though device constraints to XArray allocation is a bug and will be warned and fixed up by slab, e.g.: Unexpected gfp: 0x4 (GFP_DMA32). Fixing up to gfp: 0x82820 (GFP_ATOMIC|__GFP_NOWARN|__GFP_NOMEMALLOC). Fix your code! CPU: 2 UID: 0 PID: 1071629 Comm: kworker/u80:1 Not tainted 7.2.0-rc7+ #1 PREEMPT(lazy) Hardware name: LENOVO 21Q4/LNVNB161216, BIOS PXCN27WW 10/20/2025 Workqueue: mt76 mt792x_pm_wake_work [mt792x_lib] Call Trace: <TASK> dump_stack_lvl+0x6e/0x90 kmalloc_fix_flags+0x4d/0x6a refill_objects+0x10a/0x330 __pcs_replace_empty_main+0x292/0x5c0 kmem_cache_alloc_lru_noprof+0x4c2/0x680 ? __xas_nomem+0x3a/0x120 __xas_nomem+0x3a/0x120 __xa_alloc+0xd4/0x190 page_pool_dma_map+0xef/0x400 __page_pool_alloc_netmems_slow+0xed/0x480 ? lock_release+0x280/0x490 page_pool_alloc_frag_netmem+0xe0/0x3a0 page_pool_alloc_frag+0xe/0x20 mt76_dma_rx_fill_buf+0x1f6/0x580 [mt76] mt76_dma_rx_reset+0x1cf/0x230 [mt76] mt792x_wpdma_reset+0x183/0x1b0 [mt792x_lib] mt792x_wpdma_reinit_cond+0x5e/0xa0 [mt792x_lib] mt792xe_mcu_drv_pmctrl+0x28/0x60 [mt792x_lib] mt792x_mcu_drv_pmctrl+0x3e/0x90 [mt792x_lib] mt792x_pm_wake_work+0x2d/0x1d0 [mt792x_lib] ? process_one_work+0x20e/0x600 process_one_work+0x230/0x600 ? process_one_work+0x256/0x600 worker_thread+0x1ec/0x3c0 ? rescuer_thread+0x610/0x610 kthread+0xf2/0x130 ? kthread_affine_node+0x140/0x140 ret_from_fork+0x2a5/0x380 ? kthread_affine_node+0x140/0x140 ret_from_fork_asm+0x11/0x20 </TASK> Currently mt76 and stmmac may allocate page pool pages with GFP_DMA32. Fix it by removing zone/policy GFP flags when allocating XArray entries. This is inspired by commit 96d578088085 ("iommu/dma: Use the gfp parameter in __iommu_dma_alloc_noncontiguous()"). Fixes: ee62ce7a1d90 ("page_pool: Track DMA-mapped pages and unmap them when destroying the pool") Signed-off-by: Rong Zhang <i@rong.moe> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260821-page-pool-xa-drop-dma32-v1-1-6eab295c3478@rong.moe Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-22xdp: fix zero-copy frame layoutWeiming Shi1-2/+2
xdp_convert_zc_to_xdp_frame() clones an XSK packet into an order-0 page and advertises PAGE_SIZE as its frame size. It allows the copied frame to occupy the page tail needed by skb_shared_info and records zero headroom even when metadata separates the frame header from packet data. An AF_XDP zero-copy packet redirected through cpumap can therefore make the skb overlap skb_shared_info or place it beyond the allocated page. Limit the copied layout to SKB_WITH_OVERHEAD(PAGE_SIZE) and include the metadata length in frame headroom. Redirect callers already handle a NULL conversion result. BUG: KASAN: slab-out-of-bounds in skb_gro_receive Write of size 4 at addr ffff88800cf37004 by task cpumap/1/map:1/146 Call Trace: skb_gro_receive (net/core/gro.c:174) udp_gro_receive (net/ipv4/udp_offload.c:812) inet_gro_receive (net/ipv4/af_inet.c:1539) dev_gro_receive (net/core/gro.c:515) gro_receive_skb (net/core/gro.c:633) cpu_map_kthread_run (kernel/bpf/cpumap.c:395) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:164) ret_from_fork_asm (arch/x86/entry/entry_64.S:255) Kernel panic - not syncing: KASAN: panic_on_warn set ... Fixes: b0d1beeff2a9 ("xdp: implement convert_to_xdp_frame for MEM_TYPE_ZERO_COPY") Cc: stable@vger.kernel.org Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Link: https://patch.msgid.link/20260818154516.793517-1-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20net: core: propagate unreadable flag in skb_zerocopyMina Almasry1-1/+12
skb_zerocopy() fails to propagate the unreadable flag when copying unreadable fragments, causing target skbs to appear as readable memory. This patch fixes the flag propagation. Additionally, it returns -EFAULT if readable fragments are mixed with unreadable fragments during extraction, and returns -EFAULT in openvswitch queue_userspace_packet(). Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags") Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Bobby Eshleman <bobbyeshleman@gmail.com> Cc: Florian Westphal <fw@strlen.de> Cc: Aaron Conole <aconole@redhat.com> Cc: Eelco Chaudron <echaudro@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260814191336.187243-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>