GHSA-VCCH-Q6JX-PG5J
Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-18 18:31In 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": [],
"aliases": [
"CVE-2026-90093"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-17T17:17:00Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: access chan-\u003econn safely in get/setsockopt\n\nSince commit b66774b48dd9 (\"Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref\")\nl2cap_chan::conn has held reference and remains non-NULL also after the\ncorresponding hci_conn is deleted. In this state accessing various\nfields eg. hci_conn::hdev is invalid, which leads to KASAN crash in\nl2cap_sock_setsockopt() access of conn-\u003ehcon-\u003ehdev.\n\nCheck l2cap_chan::conn.hcon corresponds to an alive hci_conn before\ntrying to use it in l2cap_sock.c. Hold l2cap_chan_lock() in\ngetsockopt/setsockopt to ensure it stays alive, and to avoid data races\nin l2cap_chan fields.",
"id": "GHSA-vcch-q6jx-pg5j",
"modified": "2026-09-18T18:31:26Z",
"published": "2026-09-17T18:31:50Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90093"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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