# CVE-2026-90091: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan CVE-2026-90091 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-90091, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-90091 - Priority: High - CVSS: 8.0 (Moderate) - EPSS: 0.0036 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 17, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-90091 ## Description 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-207.111.5.1.el9uek | [ELSA-2026-500374](https://patchblox.com/security/data/fix/linux/elsa-2026-500374.md) | Oct 7, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-90091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90091.md) | Sep 23, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-90091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90091.md) | Sep 23, 2026 | | Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-90091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90091.md) | Sep 23, 2026 | | Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-90091](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90091.md) | Sep 23, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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