CVE-2026-90093

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb66774b48dd98f07254951f74ea6f513efe7ff8b < f49321c85785178214fd67f2e9b4b73d6363783baffected
LinuxLinuxb66774b48dd98f07254951f74ea6f513efe7ff8b < ca2c4c26498643f421d35ffe258fafbd3ed461c3affected
LinuxLinux8f90405a4a6f1f1880dc07996b47bf57c712bd8aaffected
LinuxLinux32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26baffected
LinuxLinux8922c7940bae9ce4b1736dddb6362370793835c2affected
LinuxLinux91047a4396a8b1857a6f712a90cf33ec0012b189affected
LinuxLinux0b0e2bf39cf99e458d991b9df253727e036a7d7daffected
LinuxLinuxd3b739db5dc6f688a60d56da872fabaf65246032affected
LinuxLinux50c38d9f42a529691e4e67ea9cedf4f0bfc8d277affected
LinuxLinux5.10.265 < 5.11affected
LinuxLinux5.15.216 < 5.16affected
LinuxLinux6.1.183 < 6.2affected
LinuxLinux6.6.145 < 6.7affected
LinuxLinux6.12.97 < 6.13affected
LinuxLinux6.18.39 < 6.19affected
LinuxLinux7.1.4 < 7.2affected
LinuxLinux7.2affected
LinuxLinux0 < 7.2unaffected
LinuxLinux7.2.6 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References