<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/net/xfrm, branch v7.2.3</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v7.2.3</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v7.2.3'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-09-02T12:33:19+00:00</updated>
<entry>
<title>xfrm: bound nat keepalive state collection</title>
<updated>2026-09-02T12:33:19+00:00</updated>
<author>
<name>Zihan Xi</name>
<email>zihanx@nebusec.ai</email>
</author>
<published>2026-08-17T19:09:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=3921c573d1ca49f8a8471cbb8159984d41aa8939'/>
<id>urn:sha1:3921c573d1ca49f8a8471cbb8159984d41aa8939</id>
<content type='text'>
commit 4e9442ce551ebd84b52ad649df721e2dc28af95a upstream.

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 &lt;eyal.birger@gmail.com&gt;
Reported-by: Vega &lt;vega@nebusec.ai&gt;
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi &lt;zihanx@nebusec.ai&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xfrm: fix xfrm_state_construct() auth-trunc leak</title>
<updated>2026-09-02T12:33:19+00:00</updated>
<author>
<name>Zihan Xi</name>
<email>zihanx@nebusec.ai</email>
</author>
<published>2026-07-27T17:30:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=be19d20e53a239572bb2a28efcc1cd2b069b1ef9'/>
<id>urn:sha1:be19d20e53a239572bb2a28efcc1cd2b069b1ef9</id>
<content type='text'>
commit c12cbf56320fb633484ee0ca1fb7d68d6b64b213 upstream.

attach_auth_trunc() can allocate x-&gt;aalg while leaving
x-&gt;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-&gt;props.aalgo as "no auth
algorithm attached yet" and calls attach_auth(). That overwrites
x-&gt;aalg and loses the first allocation. Any later failure or teardown
only frees the replacement pointer.

Check whether x-&gt;aalg is already attached instead of inferring that
state from x-&gt;props.aalgo.

Fixes: 4447bb33f094 ("xfrm: Store aalg in xfrm_state with a user specified truncation length")
Cc: stable@vger.kernel.org
Reported-by: Vega &lt;vega@nebusec.ai&gt;
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi &lt;zihanx@nebusec.ai&gt;
Signed-off-by: Ren Wei &lt;enjou1224z@gmail.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xfrm: avoid lock inversion in nat keepalive work</title>
<updated>2026-09-02T12:33:19+00:00</updated>
<author>
<name>Zihan Xi</name>
<email>xizh2024@lzu.edu.cn</email>
</author>
<published>2026-07-21T15:25:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a9fa05b7a1246797748d15771052639e0d3cabf1'/>
<id>urn:sha1:a9fa05b7a1246797748d15771052639e0d3cabf1</id>
<content type='text'>
commit 763fe700b7c58ad64fe5202c5638848244dd4127 upstream.

nat_keepalive_work() walks the state table while xfrm_state_walk()
holds net-&gt;xfrm.xfrm_state_lock. Its callback then acquires x-&gt;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-&gt;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 &lt;vega@nebusec.ai&gt;
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi &lt;xizh2024@lzu.edu.cn&gt;
Signed-off-by: Ren Wei &lt;enjou1224z@gmail.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xfrm: drop ESP-in-TCP packets with no ingress device</title>
<updated>2026-09-02T12:33:19+00:00</updated>
<author>
<name>Zhiling Zou</name>
<email>roxy520tt@gmail.com</email>
</author>
<published>2026-07-18T07:12:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=943d95233b8b4a88994e244fcf466f8c403d63f1'/>
<id>urn:sha1:943d95233b8b4a88994e244fcf466f8c403d63f1</id>
<content type='text'>
commit e1d7c5ac1c246ce5775f604515de0a59fbf2116e upstream.

ESP-in-TCP receives records through the TCP strparser. handle_esp()
restores skb-&gt;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-&gt;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 &lt;vega@nebusec.ai&gt;
Signed-off-by: Zhiling Zou &lt;roxy520tt@gmail.com&gt;
Assisted-by: Codex:gpt-5.4
Reviewed-by: Ren Wei &lt;enjou1224z@gmail.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xfrm: espintcp: fix UAF during close</title>
<updated>2026-09-02T12:33:19+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2026-07-16T20:54:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=54b41ad14da9a981131ab6e4d3f79321a503ea5d'/>
<id>urn:sha1:54b41ad14da9a981131ab6e4d3f79321a503ea5d</id>
<content type='text'>
commit deb232e884877bf10b4ce2580909eedec986c284 upstream.

ZDI reported and analyzed a race condition during close for espintcp
sockets:

    espintcp_close() frees emsg-&gt;skb via kfree_skb() without holding
    any socket lock. Concurrently, the xfrm_trans_reinject work queue
    invokes esp_output_tcp_finish() -&gt; espintcp_push_skb() -&gt;
    espintcp_push_msgs() -&gt; 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 == &amp;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 &lt;sd@queasysnail.net&gt;
Reviewed-by: Breno Leitao &lt;leitao@debian.org&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert</title>
<updated>2026-07-06T06:30:02+00:00</updated>
<author>
<name>Xiang Mei (Microsoft)</name>
<email>xmei5@asu.edu</email>
</author>
<published>2026-07-03T05:19:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=f38f8cce2f7e79775b3db7e8a5eacda04ac908e4'/>
<id>urn:sha1:f38f8cce2f7e79775b3db7e8a5eacda04ac908e4</id>
<content type='text'>
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 &lt;
threshold and preallocates for the rest.

prefixlen &lt; 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) &lt;xmei5@asu.edu&gt;
Reviewed-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
</entry>
<entry>
<title>xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()</title>
<updated>2026-07-06T06:29:07+00:00</updated>
<author>
<name>Chen YanJun</name>
<email>moomichen@tencent.com</email>
</author>
<published>2026-07-01T03:31:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=430ea57d6daf765e88f90046afbfd1e071cb7200'/>
<id>urn:sha1:430ea57d6daf765e88f90046afbfd1e071cb7200</id>
<content type='text'>
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-&gt;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 &lt;moomichen@tencent.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
</entry>
<entry>
<title>xfrm: clear mode callbacks after failed mode setup</title>
<updated>2026-07-06T06:29:06+00:00</updated>
<author>
<name>Cen Zhang</name>
<email>zzzccc427@gmail.com</email>
</author>
<published>2026-06-27T03:01:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2538bd3cd1ff5af655908469544ac7b7ae259386'/>
<id>urn:sha1:2538bd3cd1ff5af655908469544ac7b7ae259386</id>
<content type='text'>
xfrm_state_gc_task can run long after a failed IPTFS state setup. In the
reproduced case, __xfrm_init_state() cached x-&gt;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-&gt;mode_cbs until deferred GC ran after xfrm_iptfs had been
unloaded.

Clear x-&gt;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-&gt;mode_cbs
2. mode setup fails before mode_data
3. drop the temporary module ref
4. dead state keeps x-&gt;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-&gt;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 &lt;zzzccc427@gmail.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
</entry>
<entry>
<title>xfrm: reject optional IPTFS templates in outbound policies</title>
<updated>2026-07-02T07:22:54+00:00</updated>
<author>
<name>Antony Antony</name>
<email>antony.antony@secunet.com</email>
</author>
<published>2026-06-27T08:23:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ea528f18231ec0f33317be57f8866913b19aba6e'/>
<id>urn:sha1:ea528f18231ec0f33317be57f8866913b19aba6e</id>
<content type='text'>
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]  &lt;TASK&gt;
[   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 &lt;48&gt; 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]  &lt;/TASK&gt;

[   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] &gt;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 &lt;antony.antony@secunet.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
</entry>
<entry>
<title>xfrm: cache the offload ifindex for netlink dumps</title>
<updated>2026-07-02T07:12:58+00:00</updated>
<author>
<name>Cen Zhang</name>
<email>zzzccc427@gmail.com</email>
</author>
<published>2026-06-27T03:50:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c4a5f0071cc6d378a0e7151b60d85986aefac1f3'/>
<id>urn:sha1:c4a5f0071cc6d378a0e7151b60d85986aefac1f3</id>
<content type='text'>
copy_to_user_state_extra() only holds a reference to the outer xfrm_state.
That does not pin x-&gt;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-&gt;dev and drops the netdev
reference before the GETSA dump reaches xso_to_xuo() and reads
xso-&gt;dev-&gt;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-&gt;xso.dev                          from the SAD
3. copy_user_offload() calls        3. xfrm_dev_state_free() clears
   xso_to_xuo()                        xso-&gt;dev
4. xso-&gt;dev-&gt;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:
 &lt;TASK&gt;
 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 &lt;zzzccc427@gmail.com&gt;
Signed-off-by: Steffen Klassert &lt;steffen.klassert@secunet.com&gt;
</content>
</entry>
</feed>
