CVE-2026-90093

Published: September 19, 2026Last modified: October 6, 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.

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References

• https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3
• https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b