kernel/linux.git/net/xfrm, branch v6.19.11

xfrm: iptfs: only publish mode_data after clone setup

2026-04-02T11:25:42+00:00

commit d849a2f7309fc0616e79d13b008b0a47e0458b6e upstream. iptfs_clone_state() stores x->mode_data before allocating the reorder window. If that allocation fails, the code frees the cloned state and returns -ENOMEM, leaving x->mode_data pointing at freed memory. The xfrm clone unwind later runs destroy_state() through x->mode_data, so the failed clone path tears down IPTFS state that clone_state() already freed. Keep the cloned IPTFS state private until all allocations succeed so failed clones leave x->mode_data unset. The destroy path already handles a NULL mode_data pointer. Fixes: 6be02e3e4f37 ("xfrm: iptfs: handle reordering of received packets") Cc: stable@vger.kernel.org Signed-off-by: Paul Moses Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

xfrm: iptfs: validate inner IPv4 header length in IPTFS payload

2026-04-02T11:25:42+00:00

commit 0d10393d5eac33cbd92f7a41fddca12c41d3cb7e upstream. Add validation of the inner IPv4 packet tot_len and ihl fields parsed from decrypted IPTFS payloads in __input_process_payload(). A crafted ESP packet containing an inner IPv4 header with tot_len=0 causes an infinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the data offset never advances and the while(data < tail) loop never terminates, spinning forever in softirq context. Reject inner IPv4 packets where tot_len < ihl*4 or ihl*4 < sizeof(struct iphdr), which catches both the tot_len=0 case and malformed ihl values. The normal IP stack performs this validation in ip_rcv_core(), but IPTFS extracts and processes inner packets before they reach that layer. Reported-by: Roshan Kumar Fixes: 6c82d2433671 ("xfrm: iptfs: add basic receive packet (tunnel egress) handling") Cc: stable@vger.kernel.org Signed-off-by: Roshan Kumar Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman

xfrm: prevent policy_hthresh.work from racing with netns teardown

2026-04-02T11:25:23+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()

2026-04-02T11:25:23+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: iptfs: fix skb_put() panic on non-linear skb during reassembly

2026-04-02T11:25:23+00:00

[ Upstream commit 0b352f83cabfefdaafa806d6471f0eca117dc7d5 ] In iptfs_reassem_cont(), IP-TFS attempts to append data to the new inner packet 'newskb' that is being reassembled. First a zero-copy approach is tried if it succeeds then newskb becomes non-linear. When a subsequent fragment in the same datagram does not meet the fast-path conditions, a memory copy is performed. It calls skb_put() to append the data and as newskb is non-linear it triggers SKB_LINEAR_ASSERT check. Oops: invalid opcode: 0000 [#1] SMP NOPTI [...] RIP: 0010:skb_put+0x3c/0x40 [...] Call Trace: iptfs_reassem_cont+0x1ab/0x5e0 [xfrm_iptfs] iptfs_input_ordered+0x2af/0x380 [xfrm_iptfs] iptfs_input+0x122/0x3e0 [xfrm_iptfs] xfrm_input+0x91e/0x1a50 xfrm4_esp_rcv+0x3a/0x110 ip_protocol_deliver_rcu+0x1d7/0x1f0 ip_local_deliver_finish+0xbe/0x1e0 __netif_receive_skb_core.constprop.0+0xb56/0x1120 __netif_receive_skb_list_core+0x133/0x2b0 netif_receive_skb_list_internal+0x1ff/0x3f0 napi_complete_done+0x81/0x220 virtnet_poll+0x9d6/0x116e [virtio_net] __napi_poll.constprop.0+0x2b/0x270 net_rx_action+0x162/0x360 handle_softirqs+0xdc/0x510 __irq_exit_rcu+0xe7/0x110 irq_exit_rcu+0xe/0x20 common_interrupt+0x85/0xa0 Fix this by checking if the skb is non-linear. If it is, linearize it by calling skb_linearize(). As the initial allocation of newskb originally reserved enough tailroom for the entire reassembled packet we do not need to check if we have enough tailroom or extend it. Fixes: 5f2b6a909574 ("xfrm: iptfs: add skb-fragment sharing code") Reported-by: Hao Long Closes: https://lore.kernel.org/netdev/DGRCO9SL0T5U.JTINSHJQ9KPK@imlonghao.com/ Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin

xfrm: call xdo_dev_state_delete during state update

2026-04-02T11:25:22+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

2026-04-02T11:25:22+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

2026-04-02T11:25:22+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()

2026-03-04T12:20:51+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

2026-03-04T12:20:51+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