Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user
After commit ab4eedb790ca ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del"), l2cap_conn_del() uses conn->lock to protect access to conn->users. However, l2cap_register_user() and l2cap_unregister_user() don't use conn->lock, creating a race condition where these functions can access conn->users and conn->hchan concurrently with l2cap_conn_del().
This can lead to use-after-free and list corruption bugs, as reported by syzbot.
Fix this by changing l2cap_register_user() and l2cap_unregister_user() to use conn->lock instead of hci_dev_lock(), ensuring consistent locking for the l2cap_conn structure.
Metrics
CVSS 3.1 8.8/10
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= efc30877bd4bc85fefe98d80af60fafc86e5775e, < 11a87dd5df428a4b79a84d2790cac7f3c73f1f0d; >= f87271d21dd4ee83857ca11b94e7b4952749bbae, < c22a5e659959eb77c2fbb58a5adfaf3c3dab7abf; >= ab4eedb790cae44313759b50fe47da285e2519d5, < da3000cbe4851458a22be38bb18c0689c39fdd5f; >= ab4eedb790cae44313759b50fe47da285e2519d5, < 71030f3b3015a412133a805ff47970cdcf30c2b8; >= ab4eedb790cae44313759b50fe47da285e2519d5, < 752a6c9596dd25efd6978a73ff21f3b592668f4a; 18ab6b6078fa8191ca30a3065d57bf35d5635761; >= 6.6.84, < 6.6.130; >= 6.12.20, < 6.12.78; >= 6.13.8, < 6.14 |
| Linux | Linux | 6.14 |
References
- https://git.kernel.org/stable/c/11a87dd5df428a4b79a84d2790cac7f3c73f1f0dPatch
- https://git.kernel.org/stable/c/71030f3b3015a412133a805ff47970cdcf30c2b8Patch
- https://git.kernel.org/stable/c/752a6c9596dd25efd6978a73ff21f3b592668f4aPatch
- https://git.kernel.org/stable/c/c22a5e659959eb77c2fbb58a5adfaf3c3dab7abfPatch
- https://git.kernel.org/stable/c/da3000cbe4851458a22be38bb18c0689c39fdd5fPatch
Timeline
- Published
- Apr 3, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Modified