CVE-2026-31408

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

Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold

sco_recv_frame() reads conn->sk under sco_conn_lock() but immediately releases the lock without holding a reference to the socket. A concurrent close() can free the socket between the lock release and the subsequent sk->sk_state access, resulting in a use-after-free.

Other functions in the same file (sco_sock_timeout(), sco_conn_del()) correctly use sco_sock_hold() to safely hold a reference under the lock.

Fix by using sco_sock_hold() to take a reference before releasing the lock, and adding sock_put() on all exit paths.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/108b81514d8f2535eb16651495cefb2250528db3
• https://git.kernel.org/stable/c/45aaca995e4a7a05b272a58e7ab2fff4f611b8f1
• https://git.kernel.org/stable/c/598dbba9919c5e36c54fe1709b557d64120cb94b
• https://git.kernel.org/stable/c/7197462e90b8ce15caa1ae15d4bc2bb8cd21b11e
• https://git.kernel.org/stable/c/b0a7da0e3f7442545f071499beb36374714bb9de
• https://git.kernel.org/stable/c/d57384e27d1ebf0047e3f00a6e1181b8be9857a2
• https://git.kernel.org/stable/c/e76e8f0581ef555eacc11dbb095e602fb30a5361