CVE-2026-90093

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.

• https://git.kernel.org/stable/c/0d7b7b31ea092e17d757bd24e2e9028ba5e3a4ca
• https://git.kernel.org/stable/c/19e154d794eb4d33d99ca4a087b1cea9d5e65786
• https://git.kernel.org/stable/c/3af72bf8f73c519ee562e6963d5ff8e678924f93
• https://git.kernel.org/stable/c/737b80c97aef10404a9beed7c0ed45fcd5fc5931
• https://git.kernel.org/stable/c/8460dc49c9756a1e9288218060b4d41e1b704905
• https://git.kernel.org/stable/c/c66cd500ba1a58b3798c468fcc774ed2c8c2ec7d
• https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3
• https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b