laptop-kernel/include/net, branch master

ipv4: validate checksum_start before completing checksum

2026-10-08T18:03:47Z

If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of mischief. This was discovered and reported by Paulos, and has been reporoduced by others independently since. We really shouldn't allow such packets in, but as a defence in depth measure, let's also check before we complete the checksum. A more complete validation at input is forthcoming, but needs more work. Cc: stable@vger.kernel.org Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr") Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Reported-by: Paulos Yibelo Closes: https://lore.kernel.org/netdev/20260922030310.8684-2-habte.yibelo@gmail.com/ Signed-off-by: Michael S. Tsirkin Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/0a012b4923e189c4c593ef4f471e5ff0edbe9030.1791412497.git.mst@redhat.com Signed-off-by: Jakub Kicinski

net: mana: reserve RX buffer headroom to fix forwarding performance

2026-10-08T17:42:03Z

Commit 730ff06d3f5c ("net: mana: Use page pool fragments for RX buffers instead of full pages to improve memory efficiency.") started handing out RX buffers with zero headroom so that two buffers fit into one page at the default MTU. The MANA TX path, however, stores the per scatter-gather entry DMA mappings in `struct mana_skb_head` at skb->head, and mana_start_xmit() therefore calls skb_cow_head(skb, MANA_HEADROOM). The port advertises this requirement as ndev->needed_headroom = MANA_HEADROOM. As a result every packet that is received and then forwarded out of a MANA port fails the skb_cow() in ip_forward() and gets reallocated and copied by pskb_expand_head(). This is invisible to a plain RX or TX workload, but it puts a full skb reallocation plus memcpy on the hot path of every single forwarded packet, which is exactly what a router/NVA workload does. Restore the headroom. Note that reserving MANA_HEADROOM (232) is not enough: ip_forward() asks for LL_RESERVED_SPACE(dev), which rounds hard_header_len + needed_headroom up to HH_DATA_MOD and is 256 bytes on ethernet. Use LL_RESERVED_SPACE() directly so the value keeps tracking both constants. Also, since LL_RESERVED_SPACE() tracks MANA_HEADROOM, it grows with MAX_SKB_FRAGS and for MAX_SKB_FRAGS >= 19 it is greater than 256, so we have to account for that by using the headroom the RX queue actually uses (instead of assuming XDP_PACKET_HEADROOM) and turning MANA_XDP_MTU_MAX into MANA_XDP_MTU_MAX(ndev) (note that at the default CONFIG_MAX_SKB_FRAGS=17 they are equivalent). At the default MTU on a 4K page this means a buffer no longer fits twice into a page (SKB_DATA_ALIGN(1500 + MANA_RXBUF_PAD + 256) = 2112), so the frag-vs-single decision is now made by computing the real buffer size instead of comparing the MTU against PAGE_SIZE / 2. The page_pool fragment path is still used wherever at least two buffers genuinely fit, e.g. on 16K and 64K page sizes. Measured on an Azure VM with a MANA NIC acting as a forwarding NVA (UDP, 1400 byte payload, 4 streams, 8 Gbps offered, only the forwarding node's kernel differs), 8 runs each, median: forwarded pps throughput before 272,830 3.06 Gbps after 390,560 4.37 Gbps (+43%) perf on the forwarding node, same workload: memset_orig __pi_memcpy pskb_expand_head before 10.07% 3.96% present after 0.94% 0.64% gone Cc: stable@vger.kernel.org Fixes: 730ff06d3f5c ("net: mana: Use page pool fragments for RX buffers instead of full pages to improve memory efficiency.") Signed-off-by: Hamza Mahfooz Reviewed-by: Simon Horman Link: https://patch.msgid.link/20261003013647.2051416-1-hamzamahfooz@linux.microsoft.com Signed-off-by: Jakub Kicinski

strparser: make sure __strp_recv isn't running before tearing down the parser

2026-10-07T01:29:12Z

The comment above strp_done() claims that if strp is stopped, strp_recv will no longer be called. That's only true if the caller has a mechanism (eg locking) to guarantee that strp_recv() calls that started before strp_stop() have completed by the time we call strp_done(). This adds a dummy lock_sock/release_sock pair to guarantee that any in-flight strp_recv() (which runs under either bh_lock_sock or lock_sock, depending if it's called from ->sk_data_ready or strp_work) has completed. Only espintcp can be affected by this race condition, but this patch makes sure no future user of strp can have the bug. This could crash on strp->sk ("general mode" of strp), but this mode has been here for 9 years and has never been used. It'll be gone soon, no point worrying about it. Switch the stopped/paused/etc bits to u8's to avoid races between strp_stop() and strp_pause/unpause(). A reproducer has been published and turns the possible UAF into an exploit [1]. Reported-by: Hyunwoo Kim Link: https://lore.kernel.org/all/aZLn2Faeg1FB7XOf@v4bel/ Link: https://lore.kernel.org/all/aZgpkyTDU3aXe_V0@v4bel/ Link: https://github.com/m0x41nos/RustyTux [1] Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Cc: stable@vger.kernel.org Signed-off-by: Sabrina Dubroca Reviewed-by: Hyunwoo Kim Link: https://patch.msgid.link/425d9d926709b542ed5331110c19fee4aee1f28d.1791206940.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski

Merge tag 'linux-can-fixes-for-7.3-20261001' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

2026-10-07T01:11:19Z

Marc Kleine-Budde says: ==================== pull-request: can 2026-10-01 The first patch is by zjamg and restores the skb header initialization lost during the v7.0 release cycle. Oliver Hartkopp contributes a patch for the CAN net layer to fix the unique skb identifier regression under RPS, introduced in the v7.0 release cycle, which causes lost packets. The last patch is by Ji-Ze Hong and fixes a struct size mismatch in the f81604 CAN driver, which results in a TX starvation. * tag 'linux-can-fixes-for-7.3-20261001' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can: usb: f81604: fix struct f81604_int_data size mismatch can: fix unique skb identifier regression under RPS can: dev: init_can_skb(): restore skb header initialization ==================== Link: https://patch.msgid.link/20261001151905.1556270-1-mkl@pengutronix.de Signed-off-by: Jakub Kicinski

Merge tag 'for-net-2026-10-05' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth

2026-10-07T00:38:23Z

Luiz Augusto von Dentz says: ==================== bluetooth pull request for net: Core: - hci_sync: Fix command skb lifetime during scan setup - hci_sock: Serialize dead-device detachment - RFCOMM: free the skb when the DLC has no owner - RFCOMM: connect the session socket without rfcomm_mutex - RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown - SCO: serialise sco_conn lifetime against sco_recv_scodata() - ISO: Reject concurrent BIS listener setup - ISO: Serialize concurrent connect calls - MGMT: Fix status of pending commands flushed on power off Driver: - btintel_pcie: fix TX descriptor bounds check - btintel_pcie: use managed IRQ teardown - btintel_pcie: Add shared HW reset for clean start * tag 'for-net-2026-10-05' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth: Bluetooth: ISO: Serialize concurrent connect calls Bluetooth: ISO: Reject concurrent BIS listener setup Bluetooth: hci_sync: Fix command skb lifetime during scan setup Bluetooth: hci_sock: Serialize dead-device detachment Bluetooth: RFCOMM: Fix NULL tty_dev dereference in rfcomm_dev_shutdown Bluetooth: btintel_pcie: use managed IRQ teardown Bluetooth: MGMT: Fix status of pending commands flushed on power off Bluetooth: btintel_pcie: Add shared HW reset for clean start Bluetooth: RFCOMM: connect the session socket without rfcomm_mutex Bluetooth: btintel_pcie: fix TX descriptor bounds check Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata() Bluetooth: RFCOMM: free the skb when the DLC has no owner ==================== Link: https://patch.msgid.link/20261005194436.3594085-1-luiz.dentz@gmail.com Signed-off-by: Jakub Kicinski

amt: send the relay's General Query directly from the receive path

2026-10-02T01:11:09Z

An skb queued in a qdisc can outlive the tunnel it references through a raw pointer in skb->cb. For example, with igmp_qrv set to 1 on the relay a tunnel lives for 135s, so a netem delay of 180s on the amt device outlives it; when the tunnel expires and is freed, the subsequent dequeue triggers a use-after-free in amt_dev_xmit(). BUG: KASAN: slab-use-after-free in amt_dev_xmit+0x2763/0x2e20 Call Trace: amt_dev_xmit+0x2763/0x2e20 [drivers/net/amt.c:1262] dev_hard_start_xmit+0x22f/0x620 sch_direct_xmit+0x12e/0xac0 netem_dequeue+0x333/0xc50 net_tx_action+0x35c/0xa60 amt_send_igmp_gq() and amt_send_mld_gq() are only called from amt_request_handler(), inside the rcu_read_lock_bh() section of amt_rcv(). amt_request_handler() already has the tunnel the query is for: it found or created it inside that section. Queuing the query with dev_queue_xmit() only leads back into amt_dev_xmit(), which strips the Ethernet header and calls amt_send_membership_query() for that tunnel. Make that call directly from the two senders instead, the same way amt_send_advertisement() transmits from the receive path. The query never waits in a qdisc, the tunnel is only dereferenced inside the RCU section that found or created it, and nothing is stored in skb->cb, so no lookup or refcount is needed. Remove the query branch of amt_dev_xmit(), amt_skb_cb() and struct amt_skb_cb, which have no users left. Behaviour changes: - The relay's own General Queries no longer pass through the amt device's egress path: its qdisc, tc egress (clsact/tcx), the netfilter egress hook and packet taps. They are still visible as UDP on the underlay. - A query that is sent successfully is no longer counted as tx_dropped. The old query branch left through the unlock label, which counted every sent query as dropped. - A query that reaches amt_dev_xmit() on a relay from elsewhere, such as a userspace querier, is now dropped at the IGMP/MLD type switch. Before, it trusted whatever skb->cb held, and a NULL tunnel hit the WARN_ON(1). Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface") Reported-by: AutonomousCodeSecurity@microsoft.com Reported-by: Xiang Mei (Microsoft) Reported-by: Cen Zhang (Microsoft Security FORGE Labs) Signed-off-by: Omar Ramadan Link: https://patch.msgid.link/20260928202312.74574-2-omar@blockcast.net Signed-off-by: Jakub Kicinski

can: fix unique skb identifier regression under RPS

2026-10-01T15:05:03Z

Commit d4fb6514ff8e ("can: use skb hash instead of private variable in headroom") moved the per-skb unique identifier used for raw_rcv() duplicate detection into skb->hash. With RPS enabled, get_rps_cpu() calls skb_get_hash() before the frame reaches the CAN subsystem. Since CAN skbs have no L3/L4 headers, the flow dissector assigns every CAN frame the same non-zero software hash. can_set_skb_uid() only generated a new identifier when skb->hash was 0, so it kept this constant hash. When the SLAB allocator later reused the same skb address, raw_rcv() mistook the next legitimate frame for a duplicate and dropped it. Fix this by storing the CAN UID in the CAN skb extension (struct can_skb_ext::can_skb_uid) instead of skb->hash, decoupling it from any hash the network stack may compute. can_set_skb_uid() keeps its "assign only if unset" behaviour, which preserves UIDs set before transmission (e.g. by isotp to identify echo frames) across the local loopback path. Frames whose extension is shared with another clone (e.g. via tc mirred or netem duplicate) are given a private extension copy before the UID is assigned, so that independently received skb clones from real CAN interfaces (can_skb_uid = 0) don't end up with the same UID. The limitation that tc mirred/netem skb duplicates might be dropped in raw_rcv for looped back isotp echo frame skbs is accepted. There is no valid use-case for tc mirred or netem together with isotp which is not capable to operate on different CAN interfaces simultaneously. For routing and modifying CAN frames together with isotp use can-gw. can-gw and vxcan additionally clear the UID of forwarded/duplicated frames so each newly routed frame gets its own unique identifier. Fixes: d4fb6514ff8e ("can: use skb hash instead of private variable in headroom") Reported-by: Joerg Willmann Closes: https://lore.kernel.org/linux-can/2859AD3D-C805-41A0-9036-C5E8EE152419@clnt.de/ Cc: stable@vger.kernel.org Tested-by: Oliver Hartkopp Tested-by: Joerg Willmann Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20261001115724.27192-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

Merge tag 'nf-26-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

2026-10-01T10:00:40Z

Pablo Neira Ayuso says: ==================== Netfilter/IPVS fixes for net The following batch contains Netfilter fixes for net. This batch fixes crashes as recent feature regression, one of the due to a dependency that has been pulled into -stable: 1) Expand existing ipset fix for bitmap sets to disallow comments updates from kernel-side adds, from Florian Westphal. 2) Drop flowtable reference if nf_ct_netns_get() fails, otherwise flowtable cannot ever be removed, from Aohan Mei. 3) nft_rbtree GC should collect end elements that contained in this transaction batch, new or deleted elements are never expired. From Weiming Shi. 4) Restrict nf_nat_bpf so it does not set unknown NF_NAT_MANIP_* values, from Fernando F. Mancera. 5) Flowtable GC must skip flows that are pending hardware updates, generalize the PENDING flag and use it to inhibit GC. 6) Restore flowtable with ieee80211 which broke due to a relatively recent commit, which was pulled in by -stable, causing a regression in 6.18 kernels. And the following IPVS fixes: 1) Fix accounting of cache entries in IPVS LBLC for destinations, which eventually fills up the table and trigger recurrent resizing, from Julian Anastasov. 2) Limit IPVS cache growth for LBLCR and LBLC schedulers, from Zhiling Zou. 3) Restrict IP_VS_CONN_F_ONE_PACKET for normal connections, do not allow to use it with templates. Also from Julian. 4) Sanitize flags in IPVS sync messages received in the backup. From Julian Anastasov. netfilter pull request 26-09-30 * tag 'nf-26-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: flowtable: restore ieee80211 forward path netfilter: flowtable: generalize pending status bit netfilter: bpf: reject invalid NAT manipulation types netfilter: nft_set_rbtree: skip transaction elements during GC ipvs: filter some flags received in the backup server ipvs: do not create invisible templates ipvs: bound LBLCR and LBLC cache growth ipvs: fix missing counter decrement in lblc netfilter: nft_flow_offload: drop flowtable reference on init error path netfilter: ipset: do not update comments from kernel-side adds ==================== Link: https://patch.msgid.link/20260930074142.298353-1-pablo@netfilter.org Signed-off-by: Paolo Abeni

net: mvneta: clear XDP pfmemalloc flag between frames

2026-10-01T00:39:11Z

mvneta_swbm_add_rx_fragment() sets XDP_FLAGS_FRAGS_PF_MEMALLOC on the xdp_buff when a fragment page is a pfmemalloc one (page under memory pressure). The xdp_buff is reused for the next frame, but only the XDP_FLAGS_HAS_FRAGS bit was cleared at frame start, so the pfmemalloc bit leaked from one frame into the following ones. mvneta_swbm_build_skb() propagates the flag to skb->pfmemalloc through xdp_update_skb_frags_info(), so the skb of a subsequent fragmented frame could be wrongly marked as pfmemalloc even if none of its pages are under pressure. Clear all the xdp_buff flags in mvneta_swbm_rx_frame(), which is invoked for each new frame, instead of just the XDP_FLAGS_HAS_FRAGS bit. Fixes: ed7a58cb40bd ("net: marvell: rely on xdp_update_skb_shared_info utility routine") Reviewed-by: Simon Horman Signed-off-by: Lorenzo Bianconi Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20260929-mvneta-xdp-clear-frag-fix-v4-1-1e63b25eeed8@oss.qualcomm.com Signed-off-by: Jakub Kicinski

netfilter: flowtable: generalize pending status bit

2026-09-30T07:35:20Z

Rename NF_FLOW_HW_PENDING to NF_FLOW_PENDING and use it to inhibit the flowtable GC worker until pending hw offload work has been completed. Apparently, nf_flow_offload_stats() can schedule work to retrieve stats while the flow is being removed by GC. And this bit can also be used in a follow up patch to disable GC until the flow has been fully added in both directions. Revert the reordering done in commit d644b23afe1e ("netfilter: flowtable: publish HW_DEAD after worker is done") to prevent a race between GC and hw offload handler. Fixes: 2c8897953f3b ("netfilter: flowtable: Add pending bit for offload work") Signed-off-by: Pablo Neira Ayuso