Descripción
In the Linux kernel, 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 sockmap. After last sk_psock_put() (which usually happens when
socket removed from sockmap), sk->sk_prot gets restored and
sk->sk_prot->sock_is_readable becomes NULL.
This makes sk_is_readable() racy, if value of reloaded
after initial check. Which turn may lead to null pointer
dereference.
Ensure does not NULL after
https://git.kernel.org/stable/c/1b367ba2f94251822577daed031d6b9a9e11ba91
https://git.kernel.org/stable/c/1e0de7582ceccbdbb227d4e0ddf65732f92526da
https://git.kernel.org/stable/c/2660a544fdc0940bba15f70508a46cf9a6491230
https://git.kernel.org/stable/c/6fa68d7eab34d448a61aa24ea31e68b3231ed20d
https://git.kernel.org/stable/c/8926a7ef1977a832dd6bf702f1a99303dbf15b15
https://git.kernel.org/stable/c/c2b26638476baee154920bb587fc94ff1bf04336
https://git.kernel.org/stable/c/ff55c85a923e043d59d26b20a673a1b4a219c310
