Description
In the Linux kernel, the following vulnerability has been resolved: net: Fix TOCTOU issue in sk_is_readable() sk->sk_prot->sock_is_readable is a valid function pointer when sk resides in a sockmap. After the last sk_psock_put() (which usually happens when socket is removed from sockmap), sk->sk_prot gets restored and sk->sk_prot->sock_is_readable becomes NULL. This makes sk_is_readable() racy, if the value of sk->sk_prot is reloaded after the initial check. Which in turn may lead to a null pointer dereference. Ensure the function pointer does not turn NULL after the check.
Affected products
linux: linux kernel; debian: debian linux
References9
- git.kernel.org/stable/c/1b367ba2f94251822577daed031d6b9a9e11ba91 Patch
- git.kernel.org/stable/c/1e0de7582ceccbdbb227d4e0ddf65732f92526da Patch
- git.kernel.org/stable/c/2660a544fdc0940bba15f70508a46cf9a6491230 Patch
- git.kernel.org/stable/c/6fa68d7eab34d448a61aa24ea31e68b3231ed20d Patch
- git.kernel.org/stable/c/8926a7ef1977a832dd6bf702f1a99303dbf15b15 Patch
- git.kernel.org/stable/c/c2b26638476baee154920bb587fc94ff1bf04336 Patch
- git.kernel.org/stable/c/ff55c85a923e043d59d26b20a673a1b4a219c310 Patch
- lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
- lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
Metrics
- CVSS 3.1
-
4.7
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 4 · as of 7 November 2026
- CWE
- CWE-367
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