CVE-2026-90091
Full vulnerability record from the local CVENow database.
Description
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.
View original CVE JSON
{
"id": "CVE-2026-90091",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-17T17:17:00.563",
"lastModified": "2026-10-19T09:18:58.190",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan\n\nFor L2CAP sockets without owning sk->sk_socket, reading\nl2cap_pi(sk)->chan may race against concurrent l2cap_sock_kill() ->\nl2cap_sock_put_chan(). This excludes simultaneous proto_ops callbacks,\nbut access in l2cap_sock_cleanup_listen() has unsafe lockless read.\n\n [Task 1] [Task 2 (hdev->workqueue)]\n l2cap_sock_release(parent) l2cap_disconn_cfm\n l2cap_sock_cleanup_listen l2cap_conn_del\n bt_accept_dequeue l2cap_chan_del\n lock_sock(sk) l2cap_sock_teardown_cb\n bt_accept_unlink\n bt_sk(sk)->parent = NULL\n release_sock(sk) ----------------> lock_sock(sk)\n parent = /* NULL */\n lock_sock(sk) <--------------------- release_sock(sk)\n sock_set_flag(sk, SOCK_ZAPPED)\n l2cap_sock_close_cb\n l2cap_sock_kill(sk)\n l2cap_sock_put_chan\n chan = READ l2cap_pi(sk)->chan l2cap_pi(sk)->chan = NULL\n l2cap_chan_hold_unless_zero l2cap_put_chan(chan)\n kref_get_unless_zero(&chan->ref)\n\nTask 1 may observe NULL which causes null-ptr-deref.\n\nFix the race by taking lock_sock() in l2cap_sock_kill() to\nsynchronize with l2cap_sock_cleanup_listen(). hold_unless_zero() is not\nneeded here, l2cap_pi(sk)->chan owns reference if it is non-NULL.\n\nClarify code comments vs. locking."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"include/net/bluetooth/l2cap.h",
"net/bluetooth/l2cap_sock.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "b39298044e5534612511a2ff5de03ba5f6e7a820",
"lessThan": "827de6bd2865b22aaabd554540def3b8a33018ab",
"versionType": "git",
"status": "affected"
},
{
"version": "8c37e4338c801ebb8cee52436c01c41e009f6e87",
"lessThan": "7c7ac736b50fa259ed1bdddc18d79523f07c0442",
"versionType": "git",
"status": "affected"
},
{
"version": "84e718b6a814edc84159361f9f454a4e92ae91ae",
"lessThan": "4f8c63fe0097c9f6ea34409f82f79b3894903d91",
"versionType": "git",
"status": "affected"
},
{
"version": "36da806f7fbaee56ad9e81859deec203f9728700",
"lessThan": "61d5ddbd524c715b224cbe7e9f01da4e05098b19",
"versionType": "git",
"status": "affected"
},
{
"version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40",
"lessThan": "32a7bc6e93be36b37fe61f351d312d358195bd61",
"versionType": "git",
"status": "affected"
},
{
"version": "6fef032af0092ed5ccb767239a9ac1bc38c08a40",
"lessThan": "66d6ef18548ae6d7dd452b84115fc82c0a73a4ea",
"versionType": "git",
"status": "affected"
},
{
"version": "733e76e74e406c1d1ddc7369420dd8a47f48bb8a",
"versionType": "git",
"status": "affected"
},
{
"version": "6.1.178",
"lessThan": "6.1.188",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.6.145",
"lessThan": "6.6.157",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.12.97",
"lessThan": "6.12.110",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.18.40",
"lessThan": "6.18.52",
"versionType": "semver",
"status": "affected"
},
{
"version": "7.1.5",
"lessThan": "7.2",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"include/net/bluetooth/l2cap.h",
"net/bluetooth/l2cap_sock.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "7.2",
"status": "affected"
},
{
"version": "0",
"lessThan": "7.2",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.188",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.157",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.110",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.52",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.0,
"baseSeverity": "HIGH",
"attackVector": "ADJACENT_NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.1,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}