Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
Key facts
- Attack vector
- Adjacent network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan For L2CAP sockets without owning sk->sk_socket, reading l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() -> l2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks, but access in l2cap_sock_cleanup_listen() has unsafe lockless read. [Task 1] [Task 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_listen l2cap_conn_del bt_accept_dequeue l2cap_chan_del lock_sock(sk) l2cap_sock_teardown_cb bt_accept_unlink bt_sk(sk)->parent = NULL release_sock(sk) ----------------> lock_sock(sk) parent = /* NULL */ lock_sock(sk) <--------------------- release_sock(sk) sock_set_flag(sk, SOCK_ZAPPED) l2cap_sock_close_cb l2cap_sock_kill(sk) l2cap_sock_put_chan chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL l2cap_chan_hold_unless_zero l2cap_put_chan(chan) kref_get_unless_zero(&chan->ref) Task 1 may observe NULL which causes null-ptr-deref. Fix the race by taking lock_sock() in l2cap_sock_kill() to synchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL. Clarify code comments vs. locking.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.1.178 to before 6.1.188; 6.6.145 to before 6.6.157; 6.12.97 to before 6.12.110; 6.18.40 to before 6.18.52; 7.1.5 to before 7.2 | 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2 | Patch available | CNA |
| Linux | Linux | 7.2 and later | 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 6.1.178 to before 6.1.188; 6.6.145 to before 6.6.157; 6.12.97 to before 6.12.110; 6.18.40 to before 6.18.52; 7.1.5 to before 7.2 Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2 Patch available CNA
- Linux VendorLinux Affected 7.2 and later Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2
- Fix · CNA Linux (Linux) Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-90091
- 2026-10-03 Alias added: GHSA-xgwm-wpg9-2232
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-13 CVSS score added · Red Hat
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-29 Affected versions changed · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
Other 6
- https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab
- https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442
- https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91
- https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19
- https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61
- https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea
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Sources
- CVE-2026-90091 · CVE Program
- CVE-2026-90091 · NVD
- FIRST EPSS
- GHSA-xgwm-wpg9-2232 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-90091 · Red Hat security data · CC BY 4.0
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