Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan For L2CAP sockets without owning sk->sk_socket, reading l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() -> l2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks, but access in l2cap_sock_cleanup_listen() has unsafe lockless read. [Task 1] [Task 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_listen l2cap_conn_del bt_accept_dequeue l2cap_chan_del lock_sock(sk) l2cap_sock_teardown_cb bt_accept_unlink bt_sk(sk)->parent = NULL release_sock(sk) ----------------> lock_sock(sk) parent = /* NULL */ lock_sock(sk) <--------------------- release_sock(sk) sock_set_flag(sk, SOCK_ZAPPED) l2cap_sock_close_cb l2cap_sock_kill(sk) l2cap_sock_put_chan chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL l2cap_chan_hold_unless_zero l2cap_put_chan(chan) kref_get_unless_zero(&chan->ref) Task 1 may observe NULL which causes null-ptr-deref. Fix the race by taking lock_sock() in l2cap_sock_kill() to synchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL. Clarify code comments vs. locking.
- Products
- Kernel
- Affected versions
- Not specified
- Fixed versions
- 6.1.188, 6.12.110, 6.18.52, 6.6.157, 7.2.6
- CVEs
- CVE-2026-90091
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 8 Nov 2026, 01:41 UTC · Revision 1
Source evidence
Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
core-osv · Original sourcePublished 17 Sept 2026, 16:06 UTC
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan For L2CAP sockets without owning sk->sk_socket, reading l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() -> l2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks, but access in l2cap_sock_cleanup_listen() has unsafe lockless read. [Task 1] [Task 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_listen l2cap_conn_del bt_accept_dequeue l2cap_chan_del lock_sock(sk) l2cap_sock_teardown_cb bt_accept_unlink bt_sk(sk)->parent = NULL release_sock(sk) ----------------> lock_sock(sk) parent = /* NULL */ lock_sock(sk) <--------------------- release_sock(sk) sock_set_flag(sk, SOCK_ZAPPED) l2cap_sock_close_cb l2cap_sock_kill(sk) l2cap_sock_put_chan chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL l2cap_chan_hold_unless_zero l2cap_put_chan(chan) kref_get_unless_zero(&chan->ref) Task 1 may observe NULL which causes null-ptr-deref. Fix the race by taking lock_sock() in l2cap_sock_kill() to synchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL. Clarify code comments vs. locking.
osv:CVE-2026-90091
Kernel
Fixed versions: 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2.6
Complete source record
{
"id": "fe018ff8e6824e31e4814782e30e278585fdae86d673d685bc0b29f3aa13eed2",
"url": "https://osv.dev/vulnerability/CVE-2026-90091",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan",
"summary": "In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan For L2CAP sockets without owning sk->sk_socket, reading l2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() -> l2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks, but access in l2cap_sock_cleanup_listen() has unsafe lockless read. [Task 1] [Task 2 (hdev->workqueue)] l2cap_sock_release(parent) l2cap_disconn_cfm l2cap_sock_cleanup_listen l2cap_conn_del bt_accept_dequeue l2cap_chan_del lock_sock(sk) l2cap_sock_teardown_cb bt_accept_unlink bt_sk(sk)->parent = NULL release_sock(sk) ----------------> lock_sock(sk) parent = /* NULL */ lock_sock(sk) <--------------------- release_sock(sk) sock_set_flag(sk, SOCK_ZAPPED) l2cap_sock_close_cb l2cap_sock_kill(sk) l2cap_sock_put_chan chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL l2cap_chan_hold_unless_zero l2cap_put_chan(chan) kref_get_unless_zero(&chan->ref) Task 1 may observe NULL which causes null-ptr-deref. Fix the race by taking lock_sock() in l2cap_sock_kill() to synchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not needed here, l2cap_pi(sk)->chan owns reference if it is non-NULL. Clarify code comments vs. locking.",
"evidence": "osv:CVE-2026-90091",
"products": [
{
"name": {
"value": "Kernel",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "6.1.188",
"evidence": "/affected/1/ranges"
},
{
"value": "6.6.157",
"evidence": "/affected/1/ranges"
},
{
"value": "6.12.110",
"evidence": "/affected/1/ranges"
},
{
"value": "6.18.52",
"evidence": "/affected/1/ranges"
},
{
"value": "7.2.6",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "CVE-2026-90091",
"aliases": [
"CVE-2026-90091"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "b39298044e5534612511a2ff5de03ba5f6e7a820"
},
{
"fixed": "827de6bd2865b22aaabd554540def3b8a33018ab"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "8c37e4338c801ebb8cee52436c01c41e009f6e87"
},
{
"fixed": "7c7ac736b50fa259ed1bdddc18d79523f07c0442"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "84e718b6a814edc84159361f9f454a4e92ae91ae"
},
{
"fixed": "4f8c63fe0097c9f6ea34409f82f79b3894903d91"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "36da806f7fbaee56ad9e81859deec203f9728700"
},
{
"fixed": "61d5ddbd524c715b224cbe7e9f01da4e05098b19"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6fef032af0092ed5ccb767239a9ac1bc38c08a40"
},
{
"fixed": "32a7bc6e93be36b37fe61f351d312d358195bd61"
},
{
"fixed": "66d6ef18548ae6d7dd452b84115fc82c0a73a4ea"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.1.178"
},
{
"fixed": "6.1.188"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.6.145"
},
{
"fixed": "6.6.157"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.12.97"
},
{
"fixed": "6.12.110"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "6.18.40"
},
{
"fixed": "6.18.52"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "7.1.5"
},
{
"fixed": "7.2"
}
]
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"type": "GIT",
"events": [
{
"introduced": "733e76e74e406c1d1ddc7369420dd8a47f48bb8a"
}
]
}
],
"versions": [
"v6.1.187",
"v6.1.186",
"v6.1.185",
"v6.1.184",
"v6.1.183",
"v6.1.182",
"v6.1.181",
"v6.1.180",
"v6.1.179",
"v6.1.178",
"v6.6.156",
"v6.6.155",
"v6.6.154",
"v6.6.153",
"v6.6.152",
"v6.6.151",
"v6.6.150",
"v6.6.149",
"v6.6.148",
"v6.6.147",
"v6.6.146",
"v6.6.145",
"v6.12.109",
"v6.12.108",
"v6.12.107",
"v6.12.106",
"v6.12.105",
"v6.12.104",
"v6.12.103",
"v6.12.102",
"v6.12.101",
"v6.12.100",
"v6.12.99",
"v6.12.98",
"v6.12.97",
"v6.18.51",
"v6.18.50",
"v6.18.49",
"v6.18.48",
"v6.18.47",
"v6.18.46",
"v6.18.45",
"v6.18.44",
"v6.18.43",
"v6.18.42",
"v6.18.41",
"v6.18.40",
"v7.1.13",
"v7.1.12",
"v7.1.11",
"v7.1.10",
"v7.1.9",
"v7.1.8",
"v7.1.7",
"v7.1.6",
"v7.1.5"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90091.json"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "6.1.188"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.2.0"
},
{
"fixed": "6.6.157"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.7.0"
},
{
"fixed": "6.12.110"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.13.0"
},
{
"fixed": "6.18.52"
}
]
},
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "6.19.0"
},
{
"fixed": "7.2.6"
}
]
}
],
"package": {
"name": "Kernel",
"ecosystem": "Linux"
},
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90091.json"
}
}
],
"modified": "2026-10-28T02:30:52.588832223Z",
"provider": "osv",
"references": [
"https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61",
"https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91",
"https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19",
"https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea",
"https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442",
"https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90091.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-90091",
"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
],
"provider_metadata": {
"cna_assigner": "Linux",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90091.json"
}
},
"related_cves": [
{
"value": "CVE-2026-90091",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 521444,
"published_at": "2026-09-17T16:06:05.478+00:00"
}