kernel/linux.git/net/xfrm, branch v6.12.80

xfrm: prevent policy_hthresh.work from racing with netns teardown

2026-04-02T11:09:31+00:00

[ Upstream commit 29fe3a61bcdce398ee3955101c39f89c01a8a77e ] A XFRM_MSG_NEWSPDINFO request can queue the per-net work item policy_hthresh.work onto the system workqueue. The queued callback, xfrm_hash_rebuild(), retrieves the enclosing struct net via container_of(). If the net namespace is torn down before that work runs, the associated struct net may already have been freed, and xfrm_hash_rebuild() may then dereference stale memory. xfrm_policy_fini() already flushes policy_hash_work during teardown, but it does not synchronize policy_hthresh.work. Synchronize policy_hthresh.work in xfrm_policy_fini() as well, so the queued work cannot outlive the net namespace teardown and access a freed struct net. Fixes: 880a6fab8f6b ("xfrm: configure policy hash table thresholds by netlink") Signed-off-by: Minwoo Ra Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: Fix work re-schedule after cancel in xfrm_nat_keepalive_net_fini()

2026-04-02T11:09:31+00:00

[ Upstream commit daf8e3b253aa760ff9e96c7768a464bc1d6b3c90 ] After cancel_delayed_work_sync() is called from xfrm_nat_keepalive_net_fini(), xfrm_state_fini() flushes remaining states via __xfrm_state_delete(), which calls xfrm_nat_keepalive_state_updated() to re-schedule nat_keepalive_work. The following is a simple race scenario: cpu0 cpu1 cleanup_net() [Round 1] ops_undo_list() xfrm_net_exit() xfrm_nat_keepalive_net_fini() cancel_delayed_work_sync(nat_keepalive_work); xfrm_state_fini() xfrm_state_flush() xfrm_state_delete(x) __xfrm_state_delete(x) xfrm_nat_keepalive_state_updated(x) schedule_delayed_work(nat_keepalive_work); rcu_barrier(); net_complete_free(); net_passive_dec(net); llist_add(&net->defer_free_list, &defer_free_list); cleanup_net() [Round 2] rcu_barrier(); net_complete_free() kmem_cache_free(net_cachep, net); nat_keepalive_work() // on freed net To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync(). Fixes: f531d13bdfe3 ("xfrm: support sending NAT keepalives in ESP in UDP states") Signed-off-by: Hyunwoo Kim Reviewed-by: Sabrina Dubroca Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: Fix the usage of skb->sk

2026-04-02T11:09:30+00:00

[ Upstream commit 1620c88887b16940e00dbe57dd38c74eda9bad9e ] xfrm assumed to always have a full socket at skb->sk. This is not always true, so fix it by converting to a full socket before it is used. Signed-off-by: Steffen Klassert Reviewed-by: Eric Dumazet Stable-dep-of: 0c0eef8ccd24 ("esp: fix skb leak with espintcp and async crypto") Signed-off-by: Sasha Levin

xfrm: call xdo_dev_state_delete during state update

2026-04-02T11:09:30+00:00

[ Upstream commit 7d2fc41f91bc69acb6e01b0fa23cd7d0109a6a23 ] When we update an SA, we construct a new state and call xdo_dev_state_add, but never insert it. The existing state is updated, then we immediately destroy the new state. Since we haven't added it, we don't go through the standard state delete code, and we're skipping removing it from the device (but xdo_dev_state_free will get called when we destroy the temporary state). This is similar to commit c5d4d7d83165 ("xfrm: Fix deletion of offloaded SAs on failure."). Fixes: d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: fix the condition on x->pcpu_num in xfrm_sa_len

2026-04-02T11:09:30+00:00

[ Upstream commit b57defcf8f109da5ba9cf59b2a736606faf3d846 ] pcpu_num = 0 is a valid value. The marker for "unset pcpu_num" which makes copy_to_user_state_extra not add the XFRMA_SA_PCPU attribute is UINT_MAX. Fixes: 1ddf9916ac09 ("xfrm: Add support for per cpu xfrm state handling.") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: add missing extack for XFRMA_SA_PCPU in add_acquire and allocspi

2026-04-02T11:09:30+00:00

[ Upstream commit aa8a3f3c67235422a0c3608a8772f69ca3b7b63f ] We're returning an error caused by invalid user input without setting an extack. Add one. Fixes: 1ddf9916ac09 ("xfrm: Add support for per cpu xfrm state handling.") Signed-off-by: Sabrina Dubroca Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

espintcp: Fix race condition in espintcp_close()

2026-03-04T12:21:31+00:00

[ Upstream commit e1512c1db9e8794d8d130addd2615ec27231d994 ] This issue was discovered during a code audit. After cancel_work_sync() is called from espintcp_close(), espintcp_tx_work() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the espintcp_tx_work() worker may dereference a freed espintcp ctx or sk. The following is a simple race scenario: cpu0 cpu1 espintcp_close() cancel_work_sync(&ctx->work); espintcp_write_space() schedule_work(&ctx->work); To prevent this race condition, cancel_work_sync() is replaced with disable_work_sync(). Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Hyunwoo Kim Reviewed-by: Simon Horman Link: https://patch.msgid.link/aZSie7rEdh9Nu0eM@v4bel Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

xfrm: always flush state and policy upon NETDEV_UNREGISTER event

2026-03-04T12:21:31+00:00

[ Upstream commit 4efa91a28576054aae0e6dad9cba8fed8293aef8 ] syzbot is reporting that "struct xfrm_state" refcount is leaking. unregister_netdevice: waiting for netdevsim0 to become free. Usage count = 2 ref_tracker: netdev@ffff888052f24618 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline] netdev_tracker_alloc include/linux/netdevice.h:4412 [inline] xfrm_dev_state_add+0x3a5/0x1080 net/xfrm/xfrm_device.c:316 xfrm_state_construct net/xfrm/xfrm_user.c:986 [inline] xfrm_add_sa+0x34ff/0x5fa0 net/xfrm/xfrm_user.c:1022 xfrm_user_rcv_msg+0x58e/0xc00 net/xfrm/xfrm_user.c:3507 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550 xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3529 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f This is because commit d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") implemented xfrm_dev_unregister() as no-op despite xfrm_dev_state_add() from xfrm_state_construct() acquires a reference to "struct net_device". I guess that that commit expected that NETDEV_DOWN event is fired before NETDEV_UNREGISTER event fires, and also assumed that xfrm_dev_state_add() is called only if (dev->features & NETIF_F_HW_ESP) != 0. Sabrina Dubroca identified steps to reproduce the same symptoms as below. echo 0 > /sys/bus/netdevsim/new_device dev=$(ls -1 /sys/bus/netdevsim/devices/netdevsim0/net/) ip xfrm state add src 192.168.13.1 dst 192.168.13.2 proto esp \ spi 0x1000 mode tunnel aead 'rfc4106(gcm(aes))' $key 128 \ offload crypto dev $dev dir out ethtool -K $dev esp-hw-offload off echo 0 > /sys/bus/netdevsim/del_device Like these steps indicate, the NETIF_F_HW_ESP bit can be cleared after xfrm_dev_state_add() acquired a reference to "struct net_device". Also, xfrm_dev_state_add() does not check for the NETIF_F_HW_ESP bit when acquiring a reference to "struct net_device". Commit 03891f820c21 ("xfrm: handle NETDEV_UNREGISTER for xfrm device") re-introduced the NETDEV_UNREGISTER event to xfrm_dev_event(), but that commit for unknown reason chose to share xfrm_dev_down() between the NETDEV_DOWN event and the NETDEV_UNREGISTER event. I guess that that commit missed the behavior in the previous paragraph. Therefore, we need to re-introduce xfrm_dev_unregister() in order to release the reference to "struct net_device" by unconditionally flushing state and policy. Reported-by: syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84 Fixes: d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") Cc: Sabrina Dubroca Signed-off-by: Tetsuo Handa Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: skip templates check for packet offload tunnel mode

2026-03-04T12:21:31+00:00

[ Upstream commit 0a4524bc69882a4ddb235bb6b279597721bda197 ] In packet offload, hardware is responsible to check templates. The result of its operation is forwarded through secpath by relevant drivers. That secpath is actually removed in __xfrm_policy_check2(). In case packet is forwarded, this secpath is reset in RX, but pushed again to TX where policy is rechecked again against dummy secpath in xfrm_policy_ok(). Such situation causes to unexpected XfrmInTmplMismatch increase. As a solution, simply skip template mismatch check. Fixes: 600258d555f0 ("xfrm: delete intermediate secpath entry in packet offload mode") Signed-off-by: Leon Romanovsky Reviewed-by: Jianbo Liu Reviewed-by: Cosmin Ratiu Signed-off-by: Tariq Toukan Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: set ipv4 no_pmtu_disc flag only on output sa when direction is set

2026-01-23T10:18:35+00:00

[ Upstream commit c196def07bbc6e8306d7a274433913444b0db20a ] The XFRM_STATE_NOPMTUDISC flag is only meaningful for output SAs, but it was being applied regardless of the SA direction when the sysctl ip_no_pmtu_disc is enabled. This can unintentionally affect input SAs. Limit setting XFRM_STATE_NOPMTUDISC to output SAs when the SA direction is configured. Closes: https://github.com/strongswan/strongswan/issues/2946 Fixes: a4a87fa4e96c ("xfrm: Add Direction to the SA in or out") Signed-off-by: Antony Antony Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin