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.
Published: 2026-09-17
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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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

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-17T16:06:06.197Z

Reserved: 2026-09-11T19:38:34.786Z

Link: CVE-2026-90092

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-17T17:17:00.757

Modified: 2026-09-17T17:17:00.757

Link: CVE-2026-90092

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.