PT-2026-61262 · Linux · Linux

CVE-2026-63945 · Published 2026-07-19 · Updated 2026-07-19

NVD

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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

Bluetooth: ISO: serialize iso sock clear timer with socket lock

iso sock close() calls iso sock clear timer() before acquiring lock sock(sk).

iso sock clear timer() reads iso pi(sk)->conn twice without the socket lock held:

if (!iso pi(sk)->conn) return; cancel delayed work(&iso pi(sk)->conn->timeout work);

Concurrently, iso conn del() executes under lock sock(sk) and calls iso chan del(), which sets iso pi(sk)->conn to NULL and may result in the final reference to the connection being dropped:

CPU0 CPU1

---

iso sock clear timer() if (conn != NULL) ... lock sock(sk) iso chan del() iso pi(sk)->conn = NULL cancel delayed work(conn) /* NULL deref or UAF */

iso pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free.

Serialize iso sock clear timer() with the socket lock by moving it inside lock sock()/release sock(), matching the pattern used in iso conn del() and all other call sites.

Fix

Related Identifiers

CVE-2026-63945

Affected Products

Linux

References · 7

• https://nvd.nist.gov/vuln/detail/CVE-2026-63945 · Security Note
• https://git.kernel.org/stable/c/4b5f8e608749b7e8fa386c6e4301cf9272595859 · Note
• https://git.kernel.org/stable/c/996c2104d0726a8fe584f85b3d6327197374a348 · Note
• https://git.kernel.org/stable/c/51cb9dcfdf9a1bccf312ab2ae4b62db629f7dcd5 · Note
• https://git.kernel.org/stable/c/bc08c15746f25f41dd0508b25780d1e84acbb2ef · Note
• https://git.kernel.org/stable/c/35f68f36d9883d56dec21cf85f7556d4657fc393 · Note
• https://git.kernel.org/stable/c/d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa · Note