wireguard-linux/net/core, branch stable

net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()

2025-11-14T01:23:21Z

The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL. Fixes: 6e9e2eed4f39 ("net: ethtool: Add support for tsconfig command to get/set hwtstamp config") Closes: https://lore.kernel.org/cd6a7056-fa6d-43f8-b78a-f5e811247ba8@linux.dev Signed-off-by: Jiaming Zhang Reviewed-by: Kory Maincent Link: https://patch.msgid.link/20251111173652.749159-2-r772577952@gmail.com Signed-off-by: Jakub Kicinski

net: netpoll: fix incorrect refcount handling causing incorrect cleanup

2025-11-11T02:34:44Z

commit efa95b01da18 ("netpoll: fix use after free") incorrectly ignored the refcount and prematurely set dev->npinfo to NULL during netpoll cleanup, leading to improper behavior and memory leaks. Scenario causing lack of proper cleanup: 1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is allocated, and refcnt = 1 - Keep in mind that npinfo is shared among all netpoll instances. In this case, there is just one. 2) Another netpoll is also associated with the same NIC and npinfo->refcnt += 1. - Now dev->npinfo->refcnt = 2; - There is just one npinfo associated to the netdev. 3) When the first netpolls goes to clean up: - The first cleanup succeeds and clears np->dev->npinfo, ignoring refcnt. - It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);` - Set dev->npinfo = NULL, without proper cleanup - No ->ndo_netpoll_cleanup() is either called 4) Now the second target tries to clean up - The second cleanup fails because np->dev->npinfo is already NULL. * In this case, ops->ndo_netpoll_cleanup() was never called, and the skb pool is not cleaned as well (for the second netpoll instance) - This leaks npinfo and skbpool skbs, which is clearly reported by kmemleak. Revert commit efa95b01da18 ("netpoll: fix use after free") and adds clarifying comments emphasizing that npinfo cleanup should only happen once the refcount reaches zero, ensuring stable and correct netpoll behavior. Cc: # 3.17.x Cc: Jay Vosburgh Fixes: efa95b01da18 ("netpoll: fix use after free") Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@debian.org Signed-off-by: Jakub Kicinski

Merge tag 'net-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-11-06T16:52:30Z

Pull networking fixes from Jakub Kicinski: Including fixes from bluetooth and wireless. Current release - new code bugs: - ptp: expose raw cycles only for clocks with free-running counter - bonding: fix null-deref in actor_port_prio setting - mdio: ERR_PTR-check regmap pointer returned by device_node_to_regmap() - eth: libie: depend on DEBUG_FS when building LIBIE_FWLOG Previous releases - regressions: - virtio_net: fix perf regression due to bad alignment of virtio_net_hdr_v1_hash - Revert "wifi: ath10k: avoid unnecessary wait for service ready message" caused regressions for QCA988x and QCA9984 - Revert "wifi: ath12k: Fix missing station power save configuration" caused regressions for WCN7850 - eth: bnxt_en: shutdown FW DMA in bnxt_shutdown(), fix memory corruptions after kexec Previous releases - always broken: - virtio-net: fix received packet length check for big packets - sctp: fix races in socket diag handling - wifi: add an hrtimer-based delayed work item to avoid low granularity of timers set relatively far in the future, and use it where it matters (e.g. when performing AP-scheduled channel switch) - eth: mlx5e: - correctly propagate error in case of module EEPROM read failure - fix HW-GRO on systems with PAGE_SIZE == 64kB - dsa: b53: fixes for tagging, link configuration / RMII, FDB, multicast - phy: lan8842: implement latest errata" * tag 'net-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (63 commits) selftests/vsock: avoid false-positives when checking dmesg net: bridge: fix MST static key usage net: bridge: fix use-after-free due to MST port state bypass lan966x: Fix sleeping in atomic context bonding: fix NULL pointer dereference in actor_port_prio setting net: dsa: microchip: Fix reserved multicast address table programming net: wan: framer: pef2256: Switch to devm_mfd_add_devices() net: libwx: fix device bus LAN ID net/mlx5e: SHAMPO, Fix header formulas for higher MTUs and 64K pages net/mlx5e: SHAMPO, Fix skb size check for 64K pages net/mlx5e: SHAMPO, Fix header mapping for 64K pages net: ti: icssg-prueth: Fix fdb hash size configuration net/mlx5e: Fix return value in case of module EEPROM read error net: gro_cells: Reduce lock scope in gro_cell_poll libie: depend on DEBUG_FS when building LIBIE_FWLOG wifi: mac80211_hwsim: Limit destroy_on_close radio removal to netgroup netpoll: Fix deadlock in memory allocation under spinlock net: ethernet: ti: netcp: Standardize knav_dma_open_channel to return NULL on error virtio-net: fix received length check in big packets bnxt_en: Fix warning in bnxt_dl_reload_down() ...

net: gro_cells: Reduce lock scope in gro_cell_poll

2025-11-06T01:41:29Z

One GRO-cell device's NAPI callback can nest into the GRO-cell of another device if the underlying device is also using GRO-cell. This is the case for IPsec over vxlan. These two GRO-cells are separate devices. From lockdep's point of view it is the same because each device is sharing the same lock class and so it reports a possible deadlock assuming one device is nesting into itself. Hold the bh_lock only while accessing gro_cell::napi_skbs in gro_cell_poll(). This reduces the locking scope and avoids acquiring the same lock class multiple times. Fixes: 25718fdcbdd2 ("net: gro_cells: Use nested-BH locking for gro_cell") Reported-by: Gal Pressman Closes: https://lore.kernel.org/all/66664116-edb8-48dc-ad72-d5223696dd19@nvidia.com/ Signed-off-by: Sebastian Andrzej Siewior Link: https://patch.msgid.link/20251104153435.ty88xDQt@linutronix.de Signed-off-by: Jakub Kicinski

netpoll: Fix deadlock in memory allocation under spinlock

2025-11-05T03:17:00Z

Fix a AA deadlock in refill_skbs() where memory allocation while holding skb_pool->lock can trigger a recursive lock acquisition attempt. The deadlock scenario occurs when the system is under severe memory pressure: 1. refill_skbs() acquires skb_pool->lock (spinlock) 2. alloc_skb() is called while holding the lock 3. Memory allocator fails and calls slab_out_of_memory() 4. This triggers printk() for the OOM warning 5. The console output path calls netpoll_send_udp() 6. netpoll_send_udp() attempts to acquire the same skb_pool->lock 7. Deadlock: the lock is already held by the same CPU Call stack: refill_skbs() spin_lock_irqsave(&skb_pool->lock) <- lock acquired __alloc_skb() kmem_cache_alloc_node_noprof() slab_out_of_memory() printk() console_flush_all() netpoll_send_udp() skb_dequeue() spin_lock_irqsave(&skb_pool->lock) <- deadlock attempt This bug was exposed by commit 248f6571fd4c51 ("netpoll: Optimize skb refilling on critical path") which removed refill_skbs() from the critical path (where nested printk was being deferred), letting nested printk being called from inside refill_skbs() Refactor refill_skbs() to never allocate memory while holding the spinlock. Another possible solution to fix this problem is protecting the refill_skbs() from nested printks, basically calling printk_deferred_{enter,exit}() in refill_skbs(), then, any nested pr_warn() would be deferred. I prefer this approach, given I _think_ it might be a good idea to move the alloc_skb() from GFP_ATOMIC to GFP_KERNEL in the future, so, having the alloc_skb() outside of the lock will be necessary step. There is a possible TOCTOU issue when checking for the pool length, and queueing the new allocated skb, but, this is not an issue, given that an extra SKB in the pool is harmless and it will be eventually used. Signed-off-by: Breno Leitao Fixes: 248f6571fd4c51 ("netpoll: Optimize skb refilling on critical path") Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251103-fix_netpoll_aa-v4-1-4cfecdf6da7c@debian.org Signed-off-by: Jakub Kicinski

Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2025-11-01T01:22:26Z

Pull bpf fixes from Alexei Starovoitov: - Mark migrate_disable/enable() as always_inline to avoid issues with partial inlining (Yonghong Song) - Fix powerpc stack register definition in libbpf bpf_tracing.h (Andrii Nakryiko) - Reject negative head_room in __bpf_skb_change_head (Daniel Borkmann) - Conditionally include dynptr copy kfuncs (Malin Jonsson) - Sync pending IRQ work before freeing BPF ring buffer (Noorain Eqbal) - Do not audit capability check in x86 do_jit() (Ondrej Mosnacek) - Fix arm64 JIT of BPF_ST insn when it writes into arena memory (Puranjay Mohan) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf/arm64: Fix BPF_ST into arena memory bpf: Make migrate_disable always inline to avoid partial inlining bpf: Reject negative head_room in __bpf_skb_change_head bpf: Conditionally include dynptr copy kfuncs libbpf: Fix powerpc's stack register definition in bpf_tracing.h bpf: Do not audit capability check in do_jit() bpf: Sync pending IRQ work before freeing ring buffer

net: devmem: refresh devmem TX dst in case of route invalidation

2025-10-30T02:23:21Z

The zero-copy Device Memory (Devmem) transmit path relies on the socket's route cache (`dst_entry`) to validate that the packet is being sent via the network device to which the DMA buffer was bound. However, this check incorrectly fails and returns `-ENODEV` if the socket's route cache entry (`dst`) is merely missing or expired (`dst == NULL`). This scenario is observed during network events, such as when flow steering rules are deleted, leading to a temporary route cache invalidation. This patch fixes -ENODEV error for `net_devmem_get_binding()` by doing the following: 1. It attempts to rebuild the route via `rebuild_header()` if the route is initially missing (`dst == NULL`). This allows the TCP/IP stack to recover from transient route cache misses. 2. It uses `rcu_read_lock()` and `dst_dev_rcu()` to safely access the network device pointer (`dst_dev`) from the route, preventing use-after-free conditions if the device is concurrently removed. 3. It maintains the critical safety check by validating that the retrieved destination device (`dst_dev`) is exactly the device registered in the Devmem binding (`binding->dev`). These changes prevent unnecessary ENODEV failures while maintaining the critical safety requirement that the Devmem resources are only used on the bound network device. Reviewed-by: Bobby Eshleman Reported-by: Eric Dumazet Reported-by: Vedant Mathur Suggested-by: Eric Dumazet Fixes: bd61848900bf ("net: devmem: Implement TX path") Signed-off-by: Shivaji Kant Link: https://patch.msgid.link/20251029065420.3489943-1-shivajikant@google.com Signed-off-by: Jakub Kicinski

bpf: Reject negative head_room in __bpf_skb_change_head

2025-10-28T21:54:56Z

Yinhao et al. recently reported: Our fuzzing tool was able to create a BPF program which triggered the below BUG condition inside pskb_expand_head. [ 23.016047][T10006] kernel BUG at net/core/skbuff.c:2232! [...] [ 23.017301][T10006] RIP: 0010:pskb_expand_head+0x1519/0x1530 [...] [ 23.021249][T10006] Call Trace: [ 23.021387][T10006] [ 23.021507][T10006] ? __pfx_pskb_expand_head+0x10/0x10 [ 23.021725][T10006] __bpf_skb_change_head+0x22a/0x520 [ 23.021939][T10006] bpf_skb_change_head+0x34/0x1b0 [ 23.022143][T10006] ___bpf_prog_run+0xf70/0xb670 [ 23.022342][T10006] __bpf_prog_run32+0xed/0x140 [...] The problem is that in __bpf_skb_change_head() we need to reject a negative head_room as otherwise this propagates all the way to the pskb_expand_head() from skb_cow(). For example, if the BPF test infra passes a skb with gso_skb:1 to the BPF helper with a negative head_room of -22, then this gets passed into skb_cow(). __skb_cow() in this example calculates a delta of -86 which gets aligned to -64, and then triggers BUG_ON(nhead < 0). Thus, reject malformed negative input. Fixes: 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure") Reported-by: Yinhao Hu Reported-by: Kaiyan Mei Signed-off-by: Daniel Borkmann Signed-off-by: Martin KaFai Lau Reviewed-by: Dongliang Mu Link: https://patch.msgid.link/20251023125532.182262-1-daniel@iogearbox.net

net: datagram: introduce datagram_poll_queue for custom receive queues

2025-10-23T13:46:04Z

Some protocols using TCP encapsulation (e.g., espintcp, openvpn) deliver userspace-bound packets through a custom skb queue rather than the standard sk_receive_queue. Introduce datagram_poll_queue that accepts an explicit receive queue, and convert datagram_poll into a wrapper around datagram_poll_queue. This allows protocols with custom skb queues to reuse the core polling logic without relying on sk_receive_queue. Cc: Sabrina Dubroca Cc: Antonio Quartulli Signed-off-by: Ralf Lici Reviewed-by: Sabrina Dubroca Reviewed-by: Antonio Quartulli Link: https://patch.msgid.link/20251021100942.195010-2-ralf@mandelbit.com Signed-off-by: Paolo Abeni

net: gro_cells: fix lock imbalance in gro_cells_receive()

2025-10-22T00:41:09Z

syzbot found that the local_unlock_nested_bh() call was missing in some cases. WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.2.329/7421 is trying to acquire lock: ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: gro_cells_receive+0x404/0x790 net/core/gro_cells.c:30 but task is already holding lock: ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] ffffe8ffffd48888 ((&cell->bh_lock)){+...}-{3:3}, at: gro_cells_receive+0x404/0x790 net/core/gro_cells.c:30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((&cell->bh_lock)); lock((&cell->bh_lock)); *** DEADLOCK *** Given the introduction of @have_bh_lock variable, it seems the author intent was to have the local_unlock_nested_bh() after the @unlock label. Fixes: 25718fdcbdd2 ("net: gro_cells: Use nested-BH locking for gro_cell") Reported-by: syzbot+f9651b9a8212e1c8906f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68f65eb9.a70a0220.205af.0034.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Sebastian Andrzej Siewior Reviewed-by: David Ahern Link: https://patch.msgid.link/20251020161114.1891141-1-edumazet@google.com Signed-off-by: Jakub Kicinski