Linux Kernel TCP TIME_WAIT OOB Access via tcp_ao_established_key
CVE-2026-64518 Published on July 25, 2026
tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key().
In the Linux kernel, the following vulnerability has been resolved:
tcp: Fix out-of-bounds access for twsk in tcp_ao_established_key().
lockdep_sock_is_held() was added in tcp_ao_established_key()
by the cited commit.
It can be called from tcp_v[46]_timewait_ack() with twsk.
Since it does not have sk->sk_lock, the lockdep annotation
results in out-of-bound access.
$ pahole -C tcp_timewait_sock vmlinux | grep size
/* size: 288, cachelines: 5, members: 8 */
$ pahole -C sock vmlinux | grep sk_lock
socket_lock_t sk_lock; /* 440 192 */
Let's not use lockdep_sock_is_held() for TCP_TIME_WAIT.
Products Associated with CVE-2026-64518
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Affected Versions
Linux:- Version 051f49d5176613dea88ecf73a101c3a99f4720e9 and below 87bb3e719042f0030a6dad39118c6a6b2a491ad9 is affected.
- Version 6b2d11e2d8fc130df4708be0b6b53fd3e6b54cf6 and below 510db031ba6eb40134f84c90ef963ea4b6dfb878 is affected.
- Version 6b2d11e2d8fc130df4708be0b6b53fd3e6b54cf6 and below 29cf64d128c94cf98d1c69d8b2962d39db5ff4c6 is affected.
- Version 6b2d11e2d8fc130df4708be0b6b53fd3e6b54cf6 and below 03cb001ef87b3f8d859cf7f96329acf3d6235d29 is affected.
- Version 6.12.5 and below 6.12.92 is affected.
- Version 6.13 is affected.
- Before 6.13 is unaffected.
- Version 6.12.92, <= 6.12.* is unaffected.
- Version 6.18.34, <= 6.18.* is unaffected.
- Version 7.0.11, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.