In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN
New sk should not be added to parent socket accept queue after last
l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and
state set to BT_CLOSED, as that can result to UAF on dereferencing the
dangling parent reference.
l2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown,
due to chan->state accessed without consistent locking:
[Task 1] [Task 2]
l2cap_sock_release(parent) l2cap_connect
l2cap_sock_shutdown pchan = l2cap_global_chan_by_psm
l2cap_chan_lock(pchan)
l2cap_chan_close
l2cap_sock_teardown_cb
pchan->state = BT_CLOSED
l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan)
l2cap_new_connection
l2cap_sock_new_connection_cb
l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan)
l2cap_sock_kill(parent) /* bt_sk(sk)->parent dangling */
Fix by adding check for sk_state == BT_LISTEN after acquiring sk lock in
l2cap_sock_new_connection_cb(). Add lock_sock() around sk_state writes
where missing, to avoid data races.
Although the data races on pchan->state should be fixed too, this
defensive sk_state check probably makes sense in any case.
Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN
New sk should not be added to parent socket accept queue after last
l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and
state set to BT_CLOSED, as that can result to UAF on dereferencing the
dangling parent reference.
l2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown,
due to chan->state accessed without consistent locking:
[Task 1] [Task 2]
l2cap_sock_release(parent) l2cap_connect
l2cap_sock_shutdown pchan = l2cap_global_chan_by_psm
l2cap_chan_lock(pchan)
l2cap_chan_close
l2cap_sock_teardown_cb
pchan->state = BT_CLOSED
l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan)
l2cap_new_connection
l2cap_sock_new_connection_cb
l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan)
l2cap_sock_kill(parent) /* bt_sk(sk)->parent dangling */
Fix by adding check for sk_state == BT_LISTEN after acquiring sk lock in
l2cap_sock_new_connection_cb(). Add lock_sock() around sk_state writes
where missing, to avoid data races.
Although the data races on pchan->state should be fixed too, this
defensive sk_state check probably makes sense in any case.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN New sk should not be added to parent socket accept queue after last l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and state set to BT_CLOSED, as that can result to UAF on dereferencing the dangling parent reference. l2cap_sock_new_connection_cb() may race with parent l2cap_chan teardown, due to chan->state accessed without consistent locking: [Task 1] [Task 2] l2cap_sock_release(parent) l2cap_connect l2cap_sock_shutdown pchan = l2cap_global_chan_by_psm l2cap_chan_lock(pchan) l2cap_chan_close l2cap_sock_teardown_cb pchan->state = BT_CLOSED l2cap_chan_unlock(pchan) ------> l2cap_chan_lock(pchan) l2cap_new_connection l2cap_sock_new_connection_cb l2cap_chan_lock(pchan) <-------- l2cap_chan_unlock(pchan) l2cap_sock_kill(parent) /* bt_sk(sk)->parent dangling */ Fix by adding check for sk_state == BT_LISTEN after acquiring sk lock in l2cap_sock_new_connection_cb(). Add lock_sock() around sk_state writes where missing, to avoid data races. Although the data races on pchan->state should be fixed too, this defensive sk_state check probably makes sense in any case. | |
| Title | Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:06:06.197Z
Reserved: 2026-09-11T19:38:34.786Z
Link: CVE-2026-90092
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:00.757
Modified: 2026-09-17T17:17:00.757
Link: CVE-2026-90092
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.