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Linux Kernel SELinux SCTP Hook Dereferences sk_socket Without a Non-NULL Guarantee, Reachable from the ASCONF Softirq Path

Last refreshed2026-09-29

Status: NEW  |  Advisory ID: CVE-2026-72242

Key Details

CVECVE-2026-72242
CVSS Score / Version7.5 (High) / CVSS v3.1
Updated2026-08-23
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Proseattack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is none; integrity impact is none; availability impact is high.

What to Know

In the Linux kernel, the following vulnerability has been resolved:

selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()

selinux_sctp_bind_connect() dereferences sk->sk_socket to pass a

struct socket * to selinux_socket_bind() and

selinux_socket_connect_helper(). However, when the hook is invoked

from the ASCONF softirq path (sctp_process_asconf), there is no file

reference guaranteeing that sk->sk_socket is non-NULL. The setsockopt

callers (bindx, connectx, set_primary, sendmsg connect) hold a file

reference and are not affected.

Both selinux_socket_bind() and selinux_socket_connect_helper()

immediately resolve sock->sk, never using the struct socket * for

anything else. Refactor the inner logic into helpers that take a

struct sock * directly so that selinux_sctp_bind_connect() never needs

to touch sk->sk_socket at all. (NVD)

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-72242
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-72242