Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
CVSS score
8.0
EPSS probability
%0.4
Risk score
0.0
Published
1 mo ago
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Vulnerability description
DayBreach CVE AI Research
CVE-2026-90091 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.
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.
IMPACT: Affected Products and Software
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 8.0 | CVSS V31 | HIGH | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD |
| 8.0 | CVSS V3_1 | HIGH | CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CVE CNA |
| 6.3 | CVSS 3.x | — | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H/E:U | Microsoft MSRC |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-90091 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-90091 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
CVSS Vector Radar Chart
8.0 / 10Vulnerability Scoring Details
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HYama doğrulandı
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