net: Fix TOCTOU issue in sk_is_readable()
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.1%
exploitation probability
0.1%top 98% of all CVEs
observed exploitation
nono source reports it
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 · LinuxReferences
https://git.kernel.org/stable/c/1b367ba2f94251822577daed031d6b9a9e11ba91https://git.kernel.org/stable/c/1e0de7582ceccbdbb227d4e0ddf65732f92526dahttps://git.kernel.org/stable/c/2660a544fdc0940bba15f70508a46cf9a6491230https://git.kernel.org/stable/c/6fa68d7eab34d448a61aa24ea31e68b3231ed20dhttps://git.kernel.org/stable/c/8926a7ef1977a832dd6bf702f1a99303dbf15b15https://git.kernel.org/stable/c/c2b26638476baee154920bb587fc94ff1bf04336https://git.kernel.org/stable/c/ff55c85a923e043d59d26b20a673a1b4a219c310https://lists.debian.org/debian-lts-announce/2025/10/msg00007.htmlhttps://lists.debian.org/debian-lts-announce/2025/10/msg00008.html