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12 daysMerge tag 'ipsec-2026-08-18' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2026-08-18 1) xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full Tighten the secpath-depth check so a full chain can't write past xvec[]. 2) Add and revert "esp: do not unref managed frag pages in esp_ssg_unref()" The patch does not fully fully resolve the issue, a corrected version will follow. 3) xfrm: espintcp: fix UAF during close Synchronize espintcp close with the xfrm_trans_reinject work queue so the freed socket message isn't dereferenced again. 4) xfrm: drop ESP-in-TCP packets with no ingress device Drop queued ESP-in-TCP records whose saved ingress device has gone away, avoiding a NULL device deref in the XFRM input path. 5) xfrm: avoid lock inversion in nat keepalive work Split the NAT keepalive walk into a reference-collection phase and a per-state lock phase to break the AB-BA with state removal. This patch has some issues that are fixed with a followup patch. 6) xfrm: Fix skb double-free in xfrm_dev_direct_output() Stop freeing the skb unconditionally in xfrm_dev_direct_output(), letting local_out()'s result indicate when ownership has moved on. 7) xfrm: ah6: validate routing header segments_left Validate the segments_left/hdrlen invariant before rearranging the routing-header addresses, avoiding an OOB memmove on malformed HDRINCL packets. 8) xfrm: fix xfrm_state_construct() auth-trunc leak Detect an already-attached auth-trunc allocation by the pointer rather than inferring it from the algorithm id, so a prior attach isn't overwritten and lost. 9) xfrm: bound nat keepalive state collection Replace the per-state allocation in the NAT keepalive walk with a fixed-size batch that drains under BH-disabled locking and resumes from the cursor, bounding the worker's memory. * tag 'ipsec-2026-08-18' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: bound nat keepalive state collection Revert "esp: do not unref managed frag pages in esp_ssg_unref()" xfrm: fix xfrm_state_construct() auth-trunc leak xfrm: ah6: validate routing header segments_left xfrm: Fix skb double-free in xfrm_dev_direct_output() xfrm: avoid lock inversion in nat keepalive work xfrm: drop ESP-in-TCP packets with no ingress device xfrm: espintcp: fix UAF during close esp: do not unref managed frag pages in esp_ssg_unref() xfrm6: fix out-of-bounds write in xfrm6_input_addr() when secpath is full ==================== Link: https://patch.msgid.link/20260818092920.653034-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-18xfrm: bound nat keepalive state collectionZihan Xi
The v1 nat keepalive fix allocates a GFP_ATOMIC object for every state while collecting references for phase two. This makes the worker's temporary memory use depend on the number of states and lets -ENOMEM abort the scan. Replace the allocated list with a fixed-size batch. When the batch is full, return a private walk status so xfrm_state_walk() leaves a cursor; drain the references after the walk releases xfrm_state_lock and resume from the cursor. This bounds temporary memory use and avoids the allocation failure path. The v1 fix also moved nat_keepalive_send() out of the walk callback. Keep the phase-two drain BH-disabled, as required by local_lock_nested_bh() used by the keepalive sockets. Fixes: 763fe700b7c5 ("xfrm: avoid lock inversion in nat keepalive work") Cc: stable@vger.kernel.org Cc: Eyal Birger <eyal.birger@gmail.com> Reported-by: Vega <vega@nebusec.ai> Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-08-13net: Const qualify ctl_tables that kmemdup unconditionallyJoel Granados
Const qualify clt_table arrays in the net directory that always pass a memory duplicate to sysctl register. The template would then be in .rodata and the kmemdup'ed array would be outside. Signed-off-by: Joel Granados <joel.granados@kernel.org> Link: https://patch.msgid.link/20260810-jag-net_const_qualify-v4-2-77e888237c69@kernel.org Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-28xfrm: fix xfrm_state_construct() auth-trunc leakZihan Xi
attach_auth_trunc() can allocate x->aalg while leaving x->props.aalgo at zero when the selected auth algorithm has no sadb_alg_id. One real case is cmac(aes). xfrm_state_construct() then treats !x->props.aalgo as "no auth algorithm attached yet" and calls attach_auth(). That overwrites x->aalg and loses the first allocation. Any later failure or teardown only frees the replacement pointer. Check whether x->aalg is already attached instead of inferring that state from x->props.aalgo. Fixes: 4447bb33f094 ("xfrm: Store aalg in xfrm_state with a user specified truncation length") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Signed-off-by: Ren Wei <enjou1224z@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-23xfrm: Fix skb double-free in xfrm_dev_direct_output()Sanghyun Park
A return value other than 1 from local_out() means that the skb has been consumed or its ownership was transferred. xfrm_dev_direct_output() nevertheless frees the skb on this path, causing a double-free when netfilter drops the packet and invalidating any other owner. Return the local_out() result directly, matching the ownership handling in xfrm_output_resume(). Fixes: 5eddd76ec2fd ("xfrm: fix tunnel mode TX datapath in packet offload mode") Signed-off-by: Sanghyun Park <sanghyun.park.cnu@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-23xfrm: avoid lock inversion in nat keepalive workZihan Xi
nat_keepalive_work() walks the state table while xfrm_state_walk() holds net->xfrm.xfrm_state_lock. Its callback then acquires x->lock, which conflicts with the delete path taking the same locks in reverse order via xfrm_state_delete() and __xfrm_state_delete(). This creates an AB-BA deadlock that is reported by lockdep when a NAT keepalive worker races with SA deletion. Fix this by splitting the keepalive walk into two phases. First, collect the candidate states while the walk holds xfrm_state_lock and take a reference on each state. Then, after the walk completes, process each collected state and acquire x->lock without nesting it under xfrm_state_lock. Fixes: f531d13bdfe3 ("xfrm: support sending NAT keepalives in ESP in UDP states") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi <xizh2024@lzu.edu.cn> Signed-off-by: Ren Wei <enjou1224z@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-22Merge branch 'big-tcp-for-udp-tunnels'Paolo Abeni
Alice Mikityanska says: ==================== BIG TCP for UDP tunnels This series is a follow-up to "BIG TCP without HBH in IPv6", and it adds support for BIG TCP IPv4/IPv6 workloads in vxlan and geneve. Now that IPv6 BIG TCP doesn't require stripping the HBH in all various combinations in tunneled traffic, adding BIG TCP becomes feasible. Patch 01 adds accessors for the length field in the UDP header, as suggested by Paolo in review. The usage of udp_set_len is then added in the following patches that start using length=0 in BIG TCP UDP packets. Patches 02-04 close the gaps that prevent BIG TCP packets from going through UDP tunnel code. Patch 05 validates packets in udp_gro_receive to exclude packets with length=0 from GRO aggregation. Patch 06 is for proper formatting in tcpdump (set UDP len to 0 rather than a trimmed value on overflow). Patches 07-08 bump up tso_max_size for VXLAN and GENEVE. Patch 09 adds selftests. ====================$ Link: https://patch.msgid.link/20260710134242.216538-1-alice.kernel@fastmail.im Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-22net: Use helpers to get/set UDP len tree-wideAlice Mikityanska
Since BIG TCP for UDP tunnels will start using len=0 in the UDP header as an indicator of a GSO packet bigger than 65535 bytes, this commit introduces the following getter and setters to use tree-wide, in order to explicitly mark places where len=0 may be expected, and handle them properly: 1. udp_set_len() sets uh->len to its real value if it's not bigger than 65535, and to 0 otherwise: to be used in GSO context with aggregated packets. 2. udp_set_len_short() is to be used when the length is known to fit 16 bits. It WARNs when the caller tries to assign a bigger value if CONFIG_DEBUG_NET=y. 3. udp_get_len_short() returns len in host byte order: to be used on the RX side to deal with non-aggregated packets, or to access the raw value of the len field. 4. udp_get_len() decodes uh->len set by udp_set_len(). It checks whether the packet is GSO to guard from malformed packets. At the moment udp_set_len() is not used, a following commit will start using it after enabling len>65535 for GSO. Raw uh->len (in network byte order) is still accessed in a few places for checksum calculation purposes, and to decode len=0 in udpv6_rcv for jumbograms. udp_rcv and udpv6_rcv will be addressed by the commit that starts using udp_set_len() to set UDP len=0 for BIG TCP packets in UDP tunnels. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://patch.msgid.link/20260710134242.216538-2-alice.kernel@fastmail.im Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-20xfrm: drop ESP-in-TCP packets with no ingress deviceZhiling Zou
ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown. In that case dev_get_by_index_rcu() returns NULL. The XFRM IPv4 and IPv6 input paths both expect skb->dev to be valid while building the route lookup, so queued ESP-in-TCP data can dereference a NULL device. Drop the packet if the saved ingress device can no longer be resolved. Such a packet can no longer be routed through the normal XFRM receive path, and this preserves the existing behaviour for packets whose ingress device still exists. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Signed-off-by: Zhiling Zou <roxy520tt@gmail.com> Assisted-by: Codex:gpt-5.4 Reviewed-by: Ren Wei <enjou1224z@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-20xfrm: espintcp: fix UAF during closeSabrina Dubroca
ZDI reported and analyzed a race condition during close for espintcp sockets: espintcp_close() frees emsg->skb via kfree_skb() without holding any socket lock. Concurrently, the xfrm_trans_reinject work queue invokes esp_output_tcp_finish() -> espintcp_push_skb() -> espintcp_push_msgs() -> skb_send_sock_locked(), which reads the same skb as a data source. Fix this by adding a synchronize_rcu() call after resetting sk_prot, since esp_output_tcp_finish() runs under RCU and won't use a socket with sk_prot == &tcp_prot. Simply taking the socket lock in espintcp_close() could lead to leaks, if esp_output_tcp_finish() re-adds an skb in the slot we just freed. After this, the existing barrier() is no longer needed. Cc: stable@vger.kernel.org Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: zdi-disclosures@trendmicro.com Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-06xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsertXiang Mei (Microsoft)
xfrm_hash_rebuild()'s first loop preallocates the bins/chains the reinsert loop needs, so the reinsert (after hlist_del_rcu()) cannot allocate or fail. But its guard is inverted: it skips policies with prefixlen < threshold and preallocates for the rest. prefixlen < threshold is exactly when policy_hash_bysel() returns NULL and the reinsert takes the allocating xfrm_policy_inexact_insert() path. So the loop preallocates for the exact policies (which never allocate) and skips the inexact ones, whose bin/node is then allocated GFP_ATOMIC during reinsert. On failure the error path only WARN_ONCE()s and continues, leaving a poisoned bydst node; the next rebuild's hlist_del_rcu() dereferences LIST_POISON2 and takes a GPF. Reachable under memory pressure, deterministic via failslab. Invert the guard so preallocation covers exactly the reinserted policies; the reinsert then allocates nothing and cannot fail. Crash: Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead...] ... Workqueue: events xfrm_hash_rebuild RIP: 0010:xfrm_hash_rebuild+0x5b3/0x1190 RAX: dead000000000122 (LIST_POISON2 + offset) ... Call Trace: hlist_del_rcu (include/linux/rculist.h:599) xfrm_hash_rebuild (net/xfrm/xfrm_policy.c:1365) process_one_work (kernel/workqueue.c:3322) worker_thread (kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) ... Kernel panic - not syncing: Fatal exception in interrupt Fixes: 24969facd704 ("xfrm: policy: store inexact policies in an rhashtable") Reported-by: AutonomousCodeSecurity@microsoft.com Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-06xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()Chen YanJun
When iptfs_skb_add_frags() copies frag references from the source frag walk into a new SKB, it increments the page reference count via __skb_frag_ref() but does not propagate SKBFL_SHARED_FRAG to the destination SKB's skb_shinfo->flags. If the source SKB carries shared frags (e.g. from a page-pool backed receive path), the new inner SKB will appear to ESP as having privately owned frags. A subsequent esp_input() call for a nested transport-mode SA then takes the no-COW fast path and decrypts in place, writing over pages that are still referenced by the outer IPTFS SKB. This causes kernel-visible memory corruption and can trigger a panic. All other frag-transfer helpers in the kernel (skb_try_coalesce, skb_gro_receive, __pskb_copy_fclone, skb_shift, skb_segment) correctly propagate SKBFL_SHARED_FRAG; align iptfs_skb_add_frags() with this convention by setting the flag inside the loop immediately after __skb_frag_ref() and nr_frags++, so every exit path that attaches a frag unconditionally propagates SKBFL_SHARED_FRAG. Fixes: 5f2b6a909574 ("xfrm: iptfs: add skb-fragment sharing code") Signed-off-by: Chen YanJun <moomichen@tencent.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-06xfrm: clear mode callbacks after failed mode setupCen Zhang
xfrm_state_gc_task can run long after a failed IPTFS state setup. In the reproduced case, __xfrm_init_state() cached x->mode_cbs, IPTFS setup returned -ENOMEM before publishing mode_data, and the temporary module reference from xfrm_get_mode_cbs() was dropped immediately. The dead state then kept x->mode_cbs until deferred GC ran after xfrm_iptfs had been unloaded. Clear x->mode_cbs when mode init or clone fails before publishing mode_data. Those states never installed mode-specific state or the long-term IPTFS module pin, so deferred GC has nothing mode-specific to destroy and must not retain a callback table pointer past the temporary lookup reference. The buggy scenario involves two paths, with each column showing the order within that path: failed setup path: 1. cache x->mode_cbs 2. mode setup fails before mode_data 3. drop the temporary module ref 4. dead state keeps x->mode_cbs cached GC/unload path: 1. xfrm_state_put() queues GC work 2. xfrm_iptfs unloads later 3. xfrm_state_gc_task runs 4. GC dereferences stale x->mode_cbs This also covers the failed clone path where clone_state() returns before publishing mode_data. Validation reproduced this kernel report: Kernel panic - not syncing: Fatal exception CONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y failslab_stacktrace_filter matched xfrm_iptfs frames ack_error=-12 FAULT_INJECTION: forcing a failure BUG: unable to handle page fault Workqueue: events xfrm_state_gc_task RIP: xfrm_state_gc_task+0x142/0x650 Modules linked in: esp4_offload xfrm_user [last unloaded: xfrm_iptfs] Kernel panic - not syncing: Fatal exception Fixes: 4b3faf610cc6 ("xfrm: iptfs: add new iptfs xfrm mode impl") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-02xfrm: reject optional IPTFS templates in outbound policiesAntony Antony
syzbot reported a stack-out-of-bounds read in xfrm_state_find() which flows from xfrm_tmpl_resolve_one(). Commit 3d776e31c841 ("xfrm: Reject optional tunnel/BEET mode templates in outbound policies") disallowed optional tunnel and BEET in outbound policies to prevent this. Later when IPTFS added, it was not covered by that fix and can still trigger the out-of-bounds read; Extend the check to disallow optional IPTFS in outbound policies as well. IPTFS should be identical to tunnel mode. IN and FWD policies are not affected: xfrm_tmpl_resolve_one() is only reachable via the outbound path. Reproducer, before: ip link add dummy0 type dummy ip link set dummy0 up ip addr add 10.1.1.1/24 dev dummy0 ip xfrm policy add src 10.1.1.1/32 dst 10.1.1.2/32 dir out tmpl src fc00::dead:1 dst fc00::dead:2 proto esp reqid 1 mode iptfs level use tmpl src fc00::dead:1 dst fc00::dead:2 proto esp reqid 2 mode transport ping -W 1 -c 1 10.1.1.2 PING 10.1.1.2 (10.1.1.2) 56(84) bytes of data. [ 64.168420] ================================================================== [ 64.169977] BUG: KASAN: stack-out-of-bounds in __xfrm6_addr_hash+0x11e/0x170 [ 64.169977] Read of size 4 at addr ffff88800e1ffd20 by task ping/2844 [ 64.169977] CPU: 2 UID: 0 PID: 2844 Comm: ping Not tainted 7.1.0-rc7-00180-geb23b588430a #98 PREEMPT(full) [ 64.169977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 64.169977] Call Trace: [ 64.169977] <TASK> [ 64.169977] dump_stack_lvl+0x47/0x70 [ 64.169977] ? __xfrm6_addr_hash+0x11e/0x170 [ 64.169977] print_report+0x152/0x4b0 [ 64.169977] ? ksys_mmap_pgoff+0x6d/0xa0 [ 64.169977] ? entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 64.169977] ? rcu_read_unlock_sched+0xa/0x20 [ 64.169977] ? __virt_addr_valid+0x21b/0x230 [ 64.169977] ? __xfrm6_addr_hash+0x11e/0x170 [ 64.169977] kasan_report+0xa8/0xd0 [ 64.169977] ? __xfrm6_addr_hash+0x11e/0x170 [ 64.169977] __xfrm6_addr_hash+0x11e/0x170 [ 64.169977] __xfrm_dst_hash+0x24/0xc0 [ 64.169977] xfrm_state_find+0xa2d/0x2f90 [ 64.169977] ? __pfx_xfrm_state_find+0x10/0x10 [ 64.169977] ? __pfx_ftrace_graph_ret_addr+0x10/0x10 [ 64.169977] ? __pfx_ftrace_graph_ret_addr+0x10/0x10 [ 64.169977] xfrm_tmpl_resolve_one+0x210/0x570 [ 64.169977] ? __pfx_xfrm_tmpl_resolve_one+0x10/0x10 [ 64.169977] ? __pfx_stack_trace_consume_entry+0x10/0x10 [ 64.169977] ? kernel_text_address+0x5b/0x80 [ 64.169977] ? __kernel_text_address+0xe/0x30 [ 64.169977] ? unwind_get_return_address+0x5e/0x90 [ 64.169977] ? arch_stack_walk+0x8c/0xe0 [ 64.169977] xfrm_tmpl_resolve+0x130/0x200 [ 64.169977] ? __pfx_xfrm_tmpl_resolve+0x10/0x10 [ 64.169977] ? __pfx_xfrm_policy_inexact_lookup_rcu+0x10/0x10 [ 64.169977] ? __refcount_add_not_zero.constprop.0+0xb2/0x110 [ 64.169977] ? __pfx___refcount_add_not_zero.constprop.0+0x10/0x10 [ 64.169977] xfrm_resolve_and_create_bundle+0xd5/0x310 [ 64.169977] ? __pfx_xfrm_resolve_and_create_bundle+0x10/0x10 [ 64.169977] ? __pfx_xfrm_policy_lookup_bytype+0x10/0x10 [ 64.169977] ? __pfx_xfrm_policy_lookup_bytype+0x10/0x10 [ 64.169977] xfrm_lookup_with_ifid+0x3d8/0xb80 [ 64.169977] ? __pfx_xfrm_lookup_with_ifid+0x10/0x10 [ 64.169977] ? ip_route_output_key_hash+0xc6/0x110 [ 64.169977] ? kasan_save_track+0x10/0x30 [ 64.169977] xfrm_lookup_route+0x18/0xe0 [ 64.169977] ip4_datagram_release_cb+0x4c9/0x530 [ 64.169977] ? __pfx_ip4_datagram_release_cb+0x10/0x10 [ 64.169977] ? do_raw_spin_lock+0x71/0xc0 [ 64.169977] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 64.169977] release_sock+0xb0/0x170 [ 64.169977] udp_connect+0x43/0x50 [ 64.169977] __sys_connect+0xa6/0x100 [ 64.169977] ? alloc_fd+0x2e9/0x300 [ 64.169977] ? __pfx___sys_connect+0x10/0x10 [ 64.169977] ? preempt_latency_start+0x1f/0x70 [ 64.169977] ? fd_install+0x7e/0x150 [ 64.169977] ? rcu_read_unlock_sched+0xa/0x20 [ 64.169977] ? __sys_socket+0xdf/0x130 [ 64.169977] ? __pfx___sys_socket+0x10/0x10 [ 64.169977] ? vma_refcount_put+0x43/0xa0 [ 64.169977] __x64_sys_connect+0x7e/0x90 [ 64.169977] do_syscall_64+0x11b/0x2b0 [ 64.169977] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 64.169977] RIP: 0033:0x7f4851ecb570 [ 64.169977] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 80 3d f9 ca 0d 00 00 74 17 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 54 [ 64.169977] RSP: 002b:00007ffc830e3498 EFLAGS: 00000202 ORIG_RAX: 000000000000002a [ 64.169977] RAX: ffffffffffffffda RBX: 00007ffc830e34d0 RCX: 00007f4851ecb570 [ 64.169977] RDX: 0000000000000010 RSI: 00007ffc830e34d0 RDI: 0000000000000005 [ 64.169977] RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 [ 64.169977] R10: 0000000000000006 R11: 0000000000000202 R12: 0000000000000005 [ 64.169977] R13: 0000000000000000 R14: 00005619a863f340 R15: 0000000000000000 [ 64.169977] </TASK> [ 64.169977] The buggy address belongs to stack of task ping/2844 [ 64.169977] and is located at offset 88 in frame: [ 64.169977] ip4_datagram_release_cb+0x0/0x530 [ 64.169977] This frame has 1 object: [ 64.169977] [32, 88) 'fl4' [ 64.169977] The buggy address belongs to the physical page: [ 64.169977] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xe1ff [ 64.169977] flags: 0x4000000000000000(zone=1) [ 64.169977] raw: 4000000000000000 0000000000000000 ffffea0000387fc8 0000000000000000 [ 64.169977] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 64.169977] page dumped because: kasan: bad access detected [ 64.169977] Memory state around the buggy address: [ 64.169977] ffff88800e1ffc00: f2 f2 00 00 f3 f3 00 00 00 00 00 00 00 00 00 00 [ 64.169977] ffff88800e1ffc80: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 [ 64.169977] >ffff88800e1ffd00: 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 [ 64.169977] ^ [ 64.169977] ffff88800e1ffd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 [ 64.169977] ffff88800e1ffe00: f1 f1 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 64.169977] ================================================================== [ 64.245153] Disabling lock debugging due to kernel taint After the fix: ip xfrm policy add src 10.1.1.1/32 dst 10.1.1.2/32 dir out tmpl \ src fc00::dead:1 dst fc00::dead:2 proto esp reqid 1 mode iptfs \ level use tmpl src fc00::dead:1 dst fc00::dead:2 proto esp reqid 2 \ mode transport Error: Mode in optional template not allowed in outbound policy. Fixes: d1716d5a44c3 ("xfrm: add generic iptfs defines and functionality") Reported-by: syzbot+0ac4d84afe1066a1f3e9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6a3ceb94.43b4ff68.30a095.0004.GAE@google.com/T/ Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-02xfrm: cache the offload ifindex for netlink dumpsCen Zhang
copy_to_user_state_extra() only holds a reference to the outer xfrm_state. That does not pin x->xso.dev. NETDEV_DOWN and NETDEV_UNREGISTER can race through xfrm_dev_state_flush(), xfrm_state_delete(), and xfrm_dev_state_free(), which clears xso->dev and drops the netdev reference before the GETSA dump reaches xso_to_xuo() and reads xso->dev->ifindex. The buggy scenario involves two paths, with each column showing the order within that path: XFRM_MSG_GETSA dump path: NETDEV teardown path: 1. xfrm_get_sa() gets xfrm_state 1. xfrm_dev_state_flush() finds x 2. copy_to_user_state_extra() sees 2. xfrm_state_delete() removes x x->xso.dev from the SAD 3. copy_user_offload() calls 3. xfrm_dev_state_free() clears xso_to_xuo() xso->dev 4. xso->dev->ifindex dereferences 4. netdev_put() drops the device a detached net_device reference Avoid following the live net_device from the dump paths. Cache the attached ifindex in xfrm_dev_offload when state or policy offload is bound to a device, and serialize that snapshot instead. This preserves the user-visible XFRMA_OFFLOAD_DEV value without depending on the embedded net_device lifetime. Validation reproduced this kernel report: Oops: general protection fault Call Trace: <TASK> copy_to_user_state_extra+0xb8d/0x1370 [xfrm_user] ? __pfx_copy_to_user_state_extra+0x10/0x10 [xfrm_user] ? __asan_memset+0x23/0x50 ? srso_alias_return_thunk+0x5/0xfbef5 ? __alloc_skb+0x342/0x960 ? srso_alias_return_thunk+0x5/0xfbef5 ? __asan_memset+0x23/0x50 ? srso_alias_return_thunk+0x5/0xfbef5 ? __nlmsg_put+0x147/0x1b0 dump_one_state+0x1c7/0x3e0 [xfrm_user] xfrm_state_netlink+0xcb/0x130 [xfrm_user] ? __pfx_xfrm_state_netlink+0x10/0x10 [xfrm_user] ? srso_alias_return_thunk+0x5/0xfbef5 ? xfrm_user_state_lookup.constprop.0+0x230/0x310 [xfrm_user] xfrm_get_sa+0x102/0x250 [xfrm_user] ? __pfx_xfrm_get_sa+0x10/0x10 [xfrm_user] xfrm_user_rcv_msg+0x504/0xaa0 [xfrm_user] ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [xfrm_user] ? srso_alias_return_thunk+0x5/0xfbef5 ? stack_trace_save+0x8e/0xc0 ? __pfx_stack_trace_save+0x10/0x10 netlink_rcv_skb+0x11f/0x350 ? __pfx_xfrm_user_rcv_msg+0x10/0x10 [xfrm_user] ? __pfx_netlink_rcv_skb+0x10/0x10 ? __pfx_mutex_lock+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 xfrm_netlink_rcv+0x65/0x80 [xfrm_user] netlink_unicast+0x600/0x870 ? __pfx_netlink_unicast+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx_stack_trace_save+0x10/0x10 netlink_sendmsg+0x75d/0xc10 ? __pfx_netlink_sendmsg+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ____sys_sendmsg+0x77a/0x900 ? srso_alias_return_thunk+0x5/0xfbef5 ? __pfx_____sys_sendmsg+0x10/0x10 ? __pfx_copy_msghdr_from_user+0x10/0x10 ? release_sock+0x1a/0x1d0 ? srso_alias_return_thunk+0x5/0xfbef5 ? netlink_insert+0x143/0xec0 ___sys_sendmsg+0xff/0x180 ? __pfx____sys_sendmsg+0x10/0x10 ? _raw_spin_lock_irqsave+0x85/0xe0 ? do_getsockname+0xf9/0x170 ? srso_alias_return_thunk+0x5/0xfbef5 ? fdget+0x53/0x3b0 __sys_sendmsg+0x111/0x1a0 ? __pfx___sys_sendmsg+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __sys_getsockname+0x8c/0x100 do_syscall_64+0x102/0x5a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 07b87f9eea0c ("xfrm: Fix unregister netdevice hang on hardware offload.") Assisted-by: Codex:gpt-5.5 Signed-off-by: Cen Zhang <zzzccc427@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-07-02xfrm: fix sk_dst_cache double-free in xfrm_user_policy()Xiang Mei (Microsoft)
xfrm_user_policy() clears the socket dst cache with __sk_dst_reset(), i.e. the non-atomic __sk_dst_set(sk, NULL): it reads sk_dst_cache with rcu_dereference_protected(), stores NULL and dst_release()s the old dst. That is only safe if no other thread modifies sk_dst_cache concurrently. For a connected UDP socket that does not hold: the transmit fast path (udp_sendmsg -> sk_dst_check -> sk_dst_reset) resets the cache locklessly with an atomic xchg(). A per-socket policy change racing a send can make both sides observe the same old dst and each dst_release() it, dropping the socket's single reference twice and freeing the xfrm_dst bundle while it is still referenced: BUG: KASAN: slab-use-after-free in dst_release Write of size 4 at addr ffff88801897b6c0 by task exploit/155 Call Trace: ... dst_release (... ./include/linux/rcuref.h:109) xfrm_user_policy (./include/net/sock.h:2239 ./include/net/sock.h:2256 net/xfrm/xfrm_state.c:3053) do_ip_setsockopt (net/ipv4/ip_sockglue.c:1347) ip_setsockopt (net/ipv4/ip_sockglue.c:1417) do_sock_setsockopt (net/socket.c:2368) __sys_setsockopt (net/socket.c:2393) __x64_sys_setsockopt (net/socket.c:2396) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Reachable by an unprivileged user via a user+network namespace. Use the atomic sk_dst_reset() so the cache is cleared and released with a single xchg(): whichever side wins releases the dst once, the other sees NULL and does nothing. Behaviour is otherwise unchanged. Fixes: 2b06cdf3e688 ("xfrm: Clear sk_dst_cache when applying per-socket policy.") Fixes: be8f8284cd89 ("net: xfrm: allow clearing socket xfrm policies.") Reported-by: AutonomousCodeSecurity@microsoft.com Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-30xfrm: nat_keepalive: avoid double free on send errorQianyu Luo
nat_keepalive_send() frees the keepalive skb whenever the IPv4 or IPv6 send helper reports an error. That cleanup is only correct before the skb is handed to the output path. Once ip_build_and_send_pkt() or ip6_xmit() takes ownership, the networking stack may already have consumed the skb before returning an error, so freeing it again is unsafe. Handle the pre-handoff failure cases inside nat_keepalive_send_ipv4() and nat_keepalive_send_ipv6(), where the caller still owns the skb, and keep nat_keepalive_send() responsible only for family dispatch and the unsupported-family cleanup path. Fixes: f531d13bdfe3 ("xfrm: support sending NAT keepalives in ESP in UDP states") Cc: stable@vger.kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Signed-off-by: Qianyu Luo <qianyuluo3@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Reviewed-by: Eyal Birger <eyal.birger@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-26xfrm: fix stale skb->prev after async crypto steals a GSO segmentPetr Wozniak
skb_gso_segment() leaves the segment list head with ->prev pointing at the last segment, an invariant validate_xmit_skb_list() relies on when it sets its tail pointer (tail = skb->prev). When validate_xmit_xfrm() walks a GSO list and some segments are stolen by async crypto (->xmit() returns -EINPROGRESS), those segments are unlinked from the list but the head ->prev is never updated. If the last segment is the one stolen, the returned head still has ->prev pointing at it, even though it is now owned by the crypto engine and may be freed. validate_xmit_skb_list() later does tail->next = skb, writing through that stale pointer -- a use-after-free. Repoint skb->prev at the last retained segment before returning. Fixes: f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.") Signed-off-by: Petr Wozniak <petr.wozniak@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-26xfrm: propagate -EINPROGRESS from validate_xmit_xfrm()Petr Wozniak
validate_xmit_xfrm() returns NULL both when a packet is dropped and when it is stolen by async crypto (-EINPROGRESS from ->xmit()). Callers cannot distinguish the two cases. f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.") changed the semantics of a NULL return from "dropped" to "stolen or dropped", but __dev_queue_xmit() was not updated. On virtual/bridge interfaces (noqueue qdisc) __dev_queue_xmit() initialises rc=-ENOMEM and jumps to out: when skb is NULL, returning -ENOMEM to the caller even though the packet will be delivered correctly via xfrm_dev_resume(). Return ERR_PTR(-EINPROGRESS) from validate_xmit_xfrm() for the async case so callers can tell it apart from a real drop. Update __dev_queue_xmit() to handle ERR_PTR(-EINPROGRESS) from validate_xmit_skb() correctly. Update validate_xmit_skb_list() to use IS_ERR_OR_NULL() so that ERR_PTR(-EINPROGRESS) is not mistakenly added to the transmitted list. Fixes: f53c723902d1 ("net: Add asynchronous callbacks for xfrm on layer 2.") Suggested-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Petr Wozniak <petr.wozniak@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-23Merge tag 'ipsec-2026-06-22' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2026-06-22 1) xfrm: use compat translator only for u64 alignment mismatch Gate the XFRM_USER_COMPAT translator on COMPAT_FOR_U64_ALIGNMENT so 32-bit compat tasks on arches whose 32-bit ABI already matches the native 64-bit layout are no longer rejected with -EOPNOTSUPP. From Sanman Pradhan. 2) net: af_key: initialize alg_key_len for IPComp states Initialize the alg_key_len to 0 in the IPComp branch of pfkey_msg2xfrm_state() so an uninitialized value cannot drive xfrm_alg_len() into a slab-out-of-bounds kmemdup during XFRM_MSG_MIGRATE. From Zijing Yin. 3) xfrm: Fix dev use-after-free in xfrm async resumption Stash the original skb->dev and extend the RCU critical section across xfrm_rcv_cb() and transport_finish() to prevent a tunnel-device UAF and original-device refcount leak when a callback replaces skb->dev. From Dong Chenchen. 4) xfrm: Fix xfrm state cache insertion race Move the state-validity check inside xfrm_state_lock in the input state cache insertion path so a state cannot be killed between the check and the insert. From Herbert Xu. 5) xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] Add READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count and xfrm_policy_default to silence the KCSAN data race reported on net->xfrm.policy_count. From Eric Dumazet. 6) espintcp: use sk_msg_free_partial to fix partial send Replace the manual skmsg accounting in espintcp with sk_msg_free_partial() so the skmsg stays consistent on every iteration and the partial-send accounting bugs go away. From Sabrina Dubroca. 7) xfrm: validate selector family and prefixlen during match Reject mismatched address families in xfrm_selector_match() and bound prefixlen in addr4_match()/addr_match() to prevent the shift-out-of-bounds syzbot reported when an AF_UNSPEC selector with a large prefixlen is matched against an IPv4 flow. From Eric Dumazet. * tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: validate selector family and prefixlen during match espintcp: use sk_msg_free_partial to fix partial send xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] xfrm: Fix xfrm state cache insertion race xfrm: Fix dev use-after-free in xfrm async resumption net: af_key: initialize alg_key_len for IPComp states xfrm: use compat translator only for u64 alignment mismatch ==================== Link: https://patch.msgid.link/20260622075726.29685-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17xfrm: xfrm_interface: require CAP_NET_ADMIN in the device netns for changelinkMaoyi Xie
xfrmi_changelink() operates on at most two netns, dev_net(dev) and the interface link netns xi->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in xi->net can rewrite an interface that lives in xi->net. Gate xfrmi_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed. Reported-by: Xiao Liang <shaw.leon@gmail.com> Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/ Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260612085941.3158249-8-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-17xfrm: validate selector family and prefixlen during matchEric Dumazet
syzbot reported a shift-out-of-bounds in xfrm_selector_match() due to AF_UNSPEC selector with large prefixlen (e.g. 128) matched against IPv4 flow (when XFRM_STATE_AF_UNSPEC is set). Fix this by: - Rejecting mismatched families in xfrm_selector_match. - Returning false in addr4_match if prefixlen > 32. - Returning false in addr_match if prefixlen > 128 (prevents overflow). Fixes: 3f0ab59e6537 ("xfrm: validate new SA's prefixlen using SA family when sel.family is unset") Reported-by: syzbot+9383b1ff0df4b29ca5e6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a2fbe35.be3f099c.2836ae.0018.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-17espintcp: use sk_msg_free_partial to fix partial sendSabrina Dubroca
sk_msg_free_partial() ensures consistency of the skmsg at every iteration, without having to manually handle uncharges and offsets. This simplifies the code, and fixes some bugs in skmsg accounting when we don't send the full contents. Cc: stable@vger.kernel.org Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: Aaron Esau <aaron1esau@gmail.com> Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-17xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[]Eric Dumazet
KCSAN reported a data race involving net->xfrm.policy_count access. Add missing READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count and xfrm_policy_default. Fixes: 2518c7c2b3d7 ("[XFRM]: Hash policies when non-prefixed.") Reported-by: syzbot+d85ba1c732720b9a4097@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a2b9e96.99669fcc.12a77b.0006.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-17xfrm: Fix xfrm state cache insertion raceHerbert Xu
The xfrm input state cache insertion code checks the validity of the state before acquiring the global xfrm_state_lock. Thus it's possible for someone else to kill the state after it passed the validity check, and then the insertion will add the dead state to the cache. Fix this by moving the validity check inside the lock. This entire function is called on the input path, where BH must be off (e.g., the caller of this function xfrm_input acquires its spinlocks without disabling BH). So there is no need to disable BH here or take the RCU read lock. Remove both and replace them with an assertion that trips if BH is accidentally enabled on some future calling path. Fixes: 81a331a0e72d ("xfrm: Add an inbound percpu state cache.") Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-13Merge tag 'ipsec-next-2026-06-12' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2026-06-12 1) Replace the open-coded manual cleanup in xfrm_add_policy() error path with xfrm_policy_destroy() for consistency with xfrm_policy_construct(). From Deepanshu Kartikey. 2) Limit XFRMA_TFCPAD to a sensible maximum (max IP length, 64k) since u32 is excessive for traffic flow confidentiality padding. From David Ahern. 3) Add a new netlink message XFRM_MSG_MIGRATE_STATE that allows migrating individual IPsec SAs independently of their policies. The existing XFRM_MSG_MIGRATE is tightly coupled to policy+SA migration, lacks SPI for unique SA identification, and cannot express reqid changes or migrate Transport mode selectors. The new interface identifies the SA via SPI and mark, supports reqid changes, address family changes, encap removal, and uses an atomic create+install flow under x->lock to prevent SN/IV reuse during AEAD SA migration. From Antony Antony. * tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next: xfrm: add documentation for XFRM_MSG_MIGRATE_STATE xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATE xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration xfrm: make xfrm_dev_state_add xuo parameter const xfrm: extract address family and selector validation helpers xfrm: refactor XFRMA_MTIMER_THRESH validation into a helper xfrm: move encap and xuo into struct xfrm_migrate xfrm: add error messages to state migration xfrm: add state synchronization after migration xfrm: check family before comparing addresses in migrate xfrm: split xfrm_state_migrate into create and install functions xfrm: rename reqid in xfrm_migrate xfrm: fix NAT-related field inheritance in SA migration xfrm: allow migration from UDP encapsulated to non-encapsulated ESP xfrm: add extack to xfrm_init_state xfrm: remove redundant assignments xfrm: Reject excessive values for XFRMA_TFCPAD xfrm: cleanup error path in xfrm_add_policy() ==================== Link: https://patch.msgid.link/20260612074725.1760473-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-12xfrm: Fix dev use-after-free in xfrm async resumptionDong Chenchen
xfrm async resumption hold skb->dev refcnt until after transport_finish. However, xfrm_rcv_cb may modify skb->dev to tunnel dev without taking device reference, such as vti_rcv_cb. The subsequent async resumption will decrement the tunnel device's reference count, which lead to uaf of tunnel dev and refcnt leak of orig dev as below: unregister_netdevice: waiting for vti1 to become free. Usage count = -2 Stash the original skb->dev to fix refcnt imbalance. The new skb->dev set by xfrm_rcv_cb can race with device teardown. Extend rcu protection over xfrm_rcv_cb and transport_finish to prevent races. Fixes: 1c428b038400 ("xfrm: hold dev ref until after transport_finish NF_HOOK") Reported-by: Xu Chunxiao <xuchunxiao3@huawei.com> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-12xfrm: use compat translator only for u64 alignment mismatchSanman Pradhan
The XFRM compat layer (CONFIG_XFRM_USER_COMPAT) translates 32-bit xfrm netlink and setsockopt messages into the native 64-bit layout. It is only needed on architectures where the 32-bit and 64-bit ABIs disagree on u64 alignment, which the kernel encodes as COMPAT_FOR_U64_ALIGNMENT. That symbol is defined only by arch/x86. XFRM_USER_COMPAT depends on it, so the translator can never be built on any other architecture, including arm64, which still provides a 32-bit compat ABI (CONFIG_COMPAT) for AArch32 EL0 userspace. On arm64 the AArch32 EABI already aligns u64 to 8 bytes, identical to the AArch64 ABI, so no translation is required and the native code path is correct for 32-bit tasks. However, xfrm_user_rcv_msg() and xfrm_user_policy() gate on in_compat_syscall() alone and then call xfrm_get_translator(), which returns NULL when no translator is registered. On arm64 that is always the case, so every xfrm netlink message and the XFRM_POLICY setsockopt issued by a 32-bit task returns -EOPNOTSUPP. A 32-bit userspace process on arm64 (and on any other arch with CONFIG_COMPAT but without COMPAT_FOR_U64_ALIGNMENT) therefore cannot configure XFRM state or policy through the XFRM_USER netlink API, and cannot use the XFRM_POLICY setsockopt path, because both fail before reaching the native parser. The translator series replaced the blanket compat rejection with a translator lookup. That made the path usable on x86 when the translator is available, but left architectures that cannot build the translator permanently rejected even when their compat layout already matches the native layout. Let those architectures use the native parser instead. Gate the translator requirement on COMPAT_FOR_U64_ALIGNMENT instead of on in_compat_syscall() alone. Gating on the ABI property rather than on CONFIG_XFRM_USER_COMPAT is deliberate: on x86 with IA32_EMULATION=y but XFRM_USER_COMPAT=n, a 32-bit task must still be rejected rather than routed through the native parser, which would misread genuinely 4-byte-aligned x86-32 messages. COMPAT_FOR_U64_ALIGNMENT is the ABI property that makes the XFRM translator mandatory. Only the receive/input direction needs the guard. The send, dump and notification paths already call the translator as "if (xtr) { ... }" with no error on NULL, so on arches without a translator they no-op and the kernel emits native 64-bit-layout messages, which is what an AArch32 task expects. Tested on Juniper SRX hardware: with the fix, 32-bit IPsec userspace netlink and XFRM_POLICY setsockopt operations that previously failed with -EOPNOTSUPP now succeed; x86 behaviour is unchanged by inspection. Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Fixes: 96392ee5a13b ("xfrm/compat: Translate 32-bit user_policy from sockptr") Cc: stable@vger.kernel.org Signed-off-by: Sanman Pradhan <psanman@juniper.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-05xfrm: espintcp: do not reuse an in-progress partial sendWyatt Feng
espintcp keeps a single in-flight transmit in ctx->partial. Before building a new sk_msg, espintcp_sendmsg() first tries to flush that state through espintcp_push_msgs(). For blocking callers, espintcp_push_msgs() may return success even when the previous partial send is still pending. espintcp_sendmsg() would then reinitialize emsg->skmsg and reuse ctx->partial while the old transfer still owns that state. Do not rebuild the send message when ctx->partial is still in progress. If espintcp_push_msgs() returns with emsg->len still set, fail the new send instead of overwriting the live partial state. This is a memory-safety fix: reusing the live partial-send state can leave a stale offset attached to a new sk_msg and lead to an out-of- bounds read in the send path. tcp_sendmsg_locked() already handles waiting for send buffer memory, so the fix here is just to preserve espintcp's one-message-at-a-time transmit state. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Cc: stable@kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Assisted-by: Codex:GPT-5.4 Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-05xfrm: iptfs: fix ABBA deadlock in iptfs_destroy_state()Tristan Madani
iptfs_destroy_state() calls hrtimer_cancel() while holding a spinlock that the timer callback also acquires, leading to an ABBA deadlock on SMP systems. For the output timer (iptfs_timer): - iptfs_destroy_state() holds x->lock, calls hrtimer_cancel() - iptfs_delay_timer() callback takes x->lock For the drop timer (drop_timer): - iptfs_destroy_state() holds drop_lock, calls hrtimer_cancel() - iptfs_drop_timer() callback takes drop_lock Both timers use HRTIMER_MODE_REL_SOFT, so their callbacks run in softirq context. When hrtimer_cancel() is called for a soft timer that is currently executing on another CPU, hrtimer_cancel_wait_running() spins on softirq_expiry_lock -- the same lock held by the softirq running the callback. If the callback is blocked waiting for the spinlock held by the caller of hrtimer_cancel(), a circular dependency forms: CPU 0: holds lock_A -> waits for softirq_expiry_lock CPU 1: holds softirq_expiry_lock -> waits for lock_A Fix by calling hrtimer_cancel() before acquiring the respective locks. hrtimer_cancel() is safe to call without holding any lock and will wait for any in-progress callback to complete. For the output timer, the lock is still acquired afterwards to drain the packet queue. For the drop timer, the lock/unlock pair is removed entirely since it only existed to serialize with the timer callback, which hrtimer_cancel() already guarantees. Found by source code audit. Fixes: 4b3faf610cc6 ("xfrm: iptfs: add new iptfs xfrm mode impl") Cc: Christian Hopps <chopps@labn.net> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani <tristan@talencesecurity.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATEAntony Antony
Only accept XFRMA used in this method, reject the rest. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migrationAntony Antony
Add a new netlink method to migrate a single xfrm_state. Unlike the existing migration mechanism (SA + policy), this supports migrating only the SA and allows changing the reqid. The SA is looked up via xfrm_usersa_id, which uniquely identifies it, so old_saddr is not needed. old_daddr is carried in xfrm_usersa_id.daddr. The reqid is invariant in the old migration. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: make xfrm_dev_state_add xuo parameter constAntony Antony
The xuo pointer is not modified by xfrm_dev_state_add(); make it const. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: extract address family and selector validation helpersAntony Antony
Extract verify_xfrm_family() and verify_selector_prefixlen() from verify_newsa_info() to allow reuse by other netlink handlers. verify_xfrm_family() validates that a given address family is AF_INET or AF_INET6 (with CONFIG_IPV6 guard). verify_selector_prefixlen() validates that the selector prefix lengths are within the bounds for the given address family. No functional change. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: refactor XFRMA_MTIMER_THRESH validation into a helperAntony Antony
Extract verify_mtimer_thresh() to consolidate the XFRMA_MTIMER_THRESH validation logic shared between the add_sa and upcoming patch. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: move encap and xuo into struct xfrm_migrateAntony Antony
In preparation for an upcoming patch, move the xfrm_encap_tmpl and xfrm_user_offload pointers from separate parameters into struct xfrm_migrate, reducing the parameter count of xfrm_state_migrate_create(), xfrm_state_migrate_install() and xfrm_state_migrate() The fields are placed after the four xfrm_address_t members where the struct is naturally 8-byte aligned, avoiding padding. No functional change. Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: add error messages to state migrationAntony Antony
Add descriptive(extack) error messages for all error paths in state migration. This improves diagnostics by providing clear feedback when migration fails. After xfrm_init_state() use NL_SET_ERR_MSG_WEAK() as fallback for error paths not yet propagating extack e.g. mode_cbs->init_state() No functional change. Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: add state synchronization after migrationAntony Antony
Add xfrm_migrate_sync() to copy curlft and replay state from the old SA to the new one before installation. The function allocates no memory, so it can be called under a spinlock. In preparation for a subsequent patch in this series. A subsequent patch calls this under x->lock, atomically capturing the latest lifetime counters and replay state from the original SA and deleting it in the same critical section to prevent SN/IV reuse for XFRM_MSG_MIGRATE_STATE method. No functional change. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: check family before comparing addresses in migrateAntony Antony
When migrating between different address families, xfrm_addr_equal() cannot meaningfully compare addresses, different lengths. Only call xfrm_addr_equal() when families match, and take the xfrm_state_insert() path when addresses are equal. Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)") Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: split xfrm_state_migrate into create and install functionsAntony Antony
To prepare for subsequent patches, split xfrm_state_migrate() into two functions: - xfrm_state_migrate_create(): creates the migrated state - xfrm_state_migrate_install(): installs it into the state table splitting will help to avoid SN/IV reuse when migrating AEAD SA. And add const whenever possible. No functional change. Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: rename reqid in xfrm_migrateAntony Antony
In preparation for a later patch in this series s/reqid/old_reqid/. No functional change. Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: fix NAT-related field inheritance in SA migrationAntony Antony
During SA migration via xfrm_state_clone_and_setup(), nat_keepalive_interval was silently dropped and never copied to the new SA. mapping_maxage was unconditionally copied even when migrating to a non-encapsulated SA. Both fields are only meaningful when UDP encapsulation (NAT-T) is in use. Move mapping_maxage and add nat_keepalive_interval inside the existing if (encap) block, so both are inherited when migrating with encapsulation and correctly absent when migrating without it. Fixes: f531d13bdfe3 ("xfrm: support sending NAT keepalives in ESP in UDP states") Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: allow migration from UDP encapsulated to non-encapsulated ESPAntony Antony
The current code prevents migrating an SA from UDP encapsulation to plain ESP. This is needed when moving from a NATed path to a non-NATed one, for example when switching from IPv4+NAT to IPv6. Only copy the existing encapsulation during migration if the encap attribute is explicitly provided. Note: PF_KEY's SADB_X_MIGRATE always passes encap=NULL and never supported encapsulation in migration. PF_KEY is deprecated and was in feature freeze when UDP encapsulation was added to xfrm. Tested-by: Yan Yan <evitayan@google.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: add extack to xfrm_init_stateAntony Antony
Add a struct extack parameter to xfrm_init_state() and pass it through to __xfrm_init_state(). This allows validation errors detected during state initialization to propagate meaningful error messages back to userspace. xfrm_state_migrate() now passes extack so that errors from the XFRM_MSG_MIGRATE_STATE path are properly reported. Callers without an extack context (af_key, ipcomp4, ipcomp6) pass NULL, preserving their existing behaviour. Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: remove redundant assignmentsAntony Antony
These assignments are overwritten within the same function further down commit e8961c50ee9cc ("xfrm: Refactor migration setup during the cloning process") x->props.family = m->new_family; Which actually moved it in the commit e03c3bba351f9 ("xfrm: Fix xfrm migrate issues when address family changes") And the initial commit 80c9abaabf428 ("[XFRM]: Extension for dynamic update of endpoint address(es)") added x->props.saddr = orig->props.saddr; and memcpy(&xc->props.saddr, &m->new_saddr, sizeof(xc->props.saddr)); Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-04xfrm: policy: fix use-after-free on inexact bin in xfrm_policy_bysel_ctx()Sanghyun Park
Fix the race by pruning the bin while still holding xfrm_policy_lock, before dropping it. Use __xfrm_policy_inexact_prune_bin() directly since the lock is already held. The wrapper xfrm_policy_inexact_prune_bin() becomes unused and is removed. Race: CPU0 (XFRM_MSG_DELPOLICY) CPU1 (XFRM_MSG_NEWSPDINFO) ========================== ========================== xfrm_policy_bysel_ctx(): spin_lock_bh(xfrm_policy_lock) bin = xfrm_policy_inexact_lookup() __xfrm_policy_unlink(pol) spin_unlock_bh(xfrm_policy_lock) xfrm_policy_kill(ret) // wide window, lock not held xfrm_hash_rebuild(): spin_lock_bh(xfrm_policy_lock) __xfrm_policy_inexact_flush(): kfree_rcu(bin) // bin freed spin_unlock_bh(xfrm_policy_lock) xfrm_policy_inexact_prune_bin(bin) // UAF: bin is freed Fixes: 6be3b0db6db8 ("xfrm: policy: add inexact policy search tree infrastructure") Signed-off-by: Sanghyun Park <sanghyun.park.cnu@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-02xfrm: iptfs: fix use-after-free on first_skb in __input_process_payloadZhenghang Xiao
__input_process_payload() stores first_skb into xtfs->ra_newskb under drop_lock when starting partial reassembly, then unlocks and breaks out of the processing loop. The post-loop check reads xtfs->ra_newskb without the lock to decide whether first_skb is still owned: if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) Between spin_unlock and this read, a concurrent CPU running iptfs_reassem_cont() (or the drop_timer hrtimer) can complete reassembly, NULL xtfs->ra_newskb, and free the skb. The check then evaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb operate on the freed skb — a use-after-free in skbuff_head_cache. Replace the unlocked read with a local bool that records whether first_skb was handed to the reassembly state in the current call. The flag is set after the existing spin_unlock, before the break, using the pointer equality that is stable at that point (first_skb == skb iff first_skb was stored in ra_newskb). Fixes: 3f3339885fb3 ("xfrm: iptfs: add reusing received skb for the tunnel egress packet") Signed-off-by: Zhenghang Xiao <kipreyyy@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-06-01xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()Takao Sato
iptfs_consume_frags() transfers paged fragments from one socket buffer to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is the same class of bug that was fixed in skb_try_coalesce() for CVE-2026-46300: when fragments backed by read-only page-cache pages are merged, the marker indicating their shared nature must be preserved so that ESP can decide correctly whether in-place encryption is safe. Apply the same two-line fix used in skb_try_coalesce() to iptfs_consume_frags(). Fixes: b96ba312e21c ("xfrm: iptfs: share page fragments of inner packets") Cc: stable@vger.kernel.org # 6.14+ Signed-off-by: Takao Sato <takaosato1997@gmail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-05-26xfrm: input: hold netns during deferred transport reinjectionZhengchuan Liang
Transport-mode reinjection stores a struct net pointer in skb->cb and uses it later from xfrm_trans_reinject(). That pointer must stay valid until the deferred callback runs. Take a netns reference when queueing deferred reinjection work and drop it after the callback completes. Use maybe_get_net() so the queueing path does not revive a namespace that is already being torn down. This keeps the existing workqueue design and fixes the netns lifetime handling in one place for all users of xfrm_trans_queue_net(). Fixes: 7b3801927e52 ("xfrm: introduce xfrm_trans_queue_net") Cc: stable@kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Co-developed-by: Luxing Yin <tr0jan@lzu.edu.cn> Signed-off-by: Luxing Yin <tr0jan@lzu.edu.cn> Signed-off-by: Zhengchuan Liang <zcliangcn@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Assisted-by: Codex:gpt-5.4 Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2026-05-26xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exitUsama Arif
The struct pernet_operations docstring in include/net/net_namespace.h explicitly warns against blocking RCU primitives in .exit handlers: Exit methods using blocking RCU primitives, such as synchronize_rcu(), should be implemented via exit_batch. [...] Please, avoid synchronize_rcu() at all, where it's possible. Note that a combination of pre_exit() and exit() can be used, since a synchronize_rcu() is guaranteed between the calls. xfrm_policy_fini() violates this: it calls synchronize_rcu() before freeing the policy_bydst hash tables (so no RCU reader is mid- traversal at free time), but runs from xfrm_net_ops.exit -- once per namespace -- so a cleanup_net() of N namespaces pays N full RCU grace periods serially. Use the documented pre_exit/exit split. Move the policy flush (and the workqueue drains it depends on) into a new .pre_exit handler; xfrm_policy_fini() then runs in .exit and frees the hash tables after the synchronize_rcu_expedited() that cleanup_net() guarantees between the two phases. Providing O(1) RCU grace periods per batch instead of O(N). Observed on Linux 6.18 with a workload doing unshare(CLONE_NEWNET) at ~13/sec sustained: cleanup_net() and the netns_wq rescuer kthread both stuck in xfrm_policy_fini()'s synchronize_rcu(), >300k struct net accumulated in the cleanup queue, Percpu in /proc/meminfo climbed to 130+ GB on 256-CPU hosts, and memcg OOMs followed. setup_net and __put_net counts were balanced, ruling out a refcount leak. Fixes: 069daad4f2ae ("xfrm: Wait for RCU readers during policy netns exit") Signed-off-by: Usama Arif <usama.arif@linux.dev> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>