CVE-2026-90093

Bluetooth: L2CAP: access chan->conn safely in get/setsockopt

State: Published
Severity: 7.8 High
Published: Sep 17, 2026
Updated: Oct 30, 2026
Reserved: Sep 11, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: access chan->conn safely in get/setsockopt

Since commit b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") l2cap_chan::conn has held reference and remains non-NULL also after the corresponding hci_conn is deleted. In this state accessing various fields eg. hci_conn::hdev is invalid, which leads to KASAN crash in l2cap_sock_setsockopt() access of conn->hcon->hdev.

Check l2cap_chan::conn.hcon corresponds to an alive hci_conn before trying to use it in l2cap_sock.c. Hold l2cap_chan_lock() in getsockopt/setsockopt to ensure it stays alive, and to avoid data races in l2cap_chan fields.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	8f90405a4a6f1f1880dc07996b47bf57c712bd8a to before c66cd500ba1a58b3798c468fcc774ed2c8c2ec7dAffected 32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b to before 737b80c97aef10404a9beed7c0ed45fcd5fc5931Affected 8922c7940bae9ce4b1736dddb6362370793835c2 to before 0d7b7b31ea092e17d757bd24e2e9028ba5e3a4caAffected 91047a4396a8b1857a6f712a90cf33ec0012b189 to before 19e154d794eb4d33d99ca4a087b1cea9d5e65786Affected 0b0e2bf39cf99e458d991b9df253727e036a7d7d to before 3af72bf8f73c519ee562e6963d5ff8e678924f93Affected d3b739db5dc6f688a60d56da872fabaf65246032 to before 8460dc49c9756a1e9288218060b4d41e1b704905Affected b66774b48dd98f07254951f74ea6f513efe7ff8b to before f49321c85785178214fd67f2e9b4b73d6363783bAffected b66774b48dd98f07254951f74ea6f513efe7ff8b to before ca2c4c26498643f421d35ffe258fafbd3ed461c3Affected 50c38d9f42a529691e4e67ea9cedf4f0bfc8d277Affected 5.10.265 to before 5.10.273Affected 5.15.216 to before 5.15.224Affected 6.1.183 to before 6.1.191Affected 6.6.145 to before 6.6.160Affected 6.12.97 to before 6.12.114Affected 6.18.39 to before 6.18.57Affected 7.1.4 to before 7.2Affected
LinuxLinux	7.2Affected before 7.2Not affected 5.10.273 through 5.10.Not affected 5.15.224 through 5.15.Not affected 6.1.191 through 6.1.Not affected 6.6.160 through 6.6.Not affected 6.12.114 through 6.12.Not affected 6.18.57 through 6.18.Not affected 7.2.6 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

8f90405a4a6f1f1880dc07996b47bf57c712bd8a to before c66cd500ba1a58b3798c468fcc774ed2c8c2ec7dAffected
32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b to before 737b80c97aef10404a9beed7c0ed45fcd5fc5931Affected
8922c7940bae9ce4b1736dddb6362370793835c2 to before 0d7b7b31ea092e17d757bd24e2e9028ba5e3a4caAffected
91047a4396a8b1857a6f712a90cf33ec0012b189 to before 19e154d794eb4d33d99ca4a087b1cea9d5e65786Affected
0b0e2bf39cf99e458d991b9df253727e036a7d7d to before 3af72bf8f73c519ee562e6963d5ff8e678924f93Affected
d3b739db5dc6f688a60d56da872fabaf65246032 to before 8460dc49c9756a1e9288218060b4d41e1b704905Affected
b66774b48dd98f07254951f74ea6f513efe7ff8b to before f49321c85785178214fd67f2e9b4b73d6363783bAffected
b66774b48dd98f07254951f74ea6f513efe7ff8b to before ca2c4c26498643f421d35ffe258fafbd3ed461c3Affected
50c38d9f42a529691e4e67ea9cedf4f0bfc8d277Affected
5.10.265 to before 5.10.273Affected
5.15.216 to before 5.15.224Affected
6.1.183 to before 6.1.191Affected
6.6.145 to before 6.6.160Affected
6.12.97 to before 6.12.114Affected
6.18.39 to before 6.18.57Affected
7.1.4 to before 7.2Affected

LinuxLinux

7.2Affected
before 7.2Not affected
5.10.273 through 5.10.*Not affected
5.15.224 through 5.15.*Not affected
6.1.191 through 6.1.*Not affected
6.6.160 through 6.6.*Not affected
6.12.114 through 6.12.*Not affected
6.18.57 through 6.18.*Not affected
7.2.6 through 7.2.*Not affected
7.3 and laterNot affected

References

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