CVE-2026-31507

A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SMC) module. A local user can exploit this vulnerability by using the tee(2) system call to duplicate a splice pipe buffer, leading to a double-free condition. This double-free can result in a use-after-free error and a kernel null pointer dereference, ultimately causing a kernel panic and a denial of service on the affected system.

Upstream rejects tee()/splice_pipe_to_pipe() paths that would duplicate SMC pipe buffers because refcounting alone cannot fix receive-window accounting. Red Hat advises patched kernels for SMC users. Unload smc where the protocol is unused.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the smc module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.