af_unix: Reject SIOCATMARK on non-stream sockets
In the Linux kernel, the following vulnerability has been resolved: af_unix: Reject SIOCATMARK on non-stream sockets SIOCATMARK reports whether the receive queue is at the urgent mark for MSG_OOB. In AF_UNIX, MSG_OOB is supported only for SOCK_STREAM sockets. SOCK_DGRAM and SOCK_SEQPACKET reject MSG_OOB in sendmsg() and recvmsg(), so they should not support SIOCATMARK either. Return -EOPNOTSUPP for non-stream sockets before checking the receive queue.
02 / AFFECTED SOFTWARE
Affected packages
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: af_unix: Reject SIOCATMARK on non-stream sockets SIOCATMARK reports whether the receive queue is at the urgent mark for MSG_OOB. In AF_UNIX, MSG_OOB is supported only for SOCK_STREAM sockets. SOCK_DGRAM and SOCK_SEQPACKET reject MSG_OOB in sendmsg() and recvmsg(), so they should not support SIOCATMARK either. Return -EOPNOTSUPP for non-stream sockets before checking the receive queue.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/3147ddf5a41c20c45c2eb69e00b62f10f822056a
- https://git.kernel.org/stable/c/645b1ed3259af38b7814242a420bc2081bdd1eb6
- https://git.kernel.org/stable/c/b741c9c6ef59f17c1f104ddf1217ef77f79ed29b
- https://git.kernel.org/stable/c/c34c41446acf6c0d13b5b06c809be11e0f7f2729
- https://git.kernel.org/stable/c/d119775f2bad827edc28071c061fdd4a91f889a5
- https://git.kernel.org/stable/c/ec123873fdc83e7244c8ed6d17b8f8ea6c416a67
- https://git.kernel.org/stable/c/f085971de6d6b8ef946a5e0bcd73ff24509a0f85
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52928.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-52928