{"id":"CVE-2026-90091","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs","summary":"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 concurr…","severity":"high","cvss":8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= b39298044e5534612511a2ff5de03ba5f6e7a820 < 827de6bd2865b22aaabd554540def3b8a33018ab","Linux >= 8c37e4338c801ebb8cee52436c01c41e009f6e87 < 7c7ac736b50fa259ed1bdddc18d79523f07c0442","Linux >= 84e718b6a814edc84159361f9f454a4e92ae91ae < 4f8c63fe0097c9f6ea34409f82f79b3894903d91","Linux >= 36da806f7fbaee56ad9e81859deec203f9728700 < 61d5ddbd524c715b224cbe7e9f01da4e05098b19","Linux >= 6fef032af0092ed5ccb767239a9ac1bc38c08a40 < 32a7bc6e93be36b37fe61f351d312d358195bd61","Linux >= 6fef032af0092ed5ccb767239a9ac1bc38c08a40 < 66d6ef18548ae6d7dd452b84115fc82c0a73a4ea","Linux 733e76e74e406c1d1ddc7369420dd8a47f48bb8a","Linux >= 6.1.178 < 6.1.188","Linux >= 6.6.145 < 6.6.157","Linux >= 6.12.97 < 6.12.110","Linux >= 6.18.40 < 6.18.52","Linux >= 7.1.5 < 7.2","Linux 7.2"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:41.277","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90091","references":[{"url":"https://git.kernel.org/stable/c/32a7bc6e93be36b37fe61f351d312d358195bd61","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4f8c63fe0097c9f6ea34409f82f79b3894903d91","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/61d5ddbd524c715b224cbe7e9f01da4e05098b19","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/66d6ef18548ae6d7dd452b84115fc82c0a73a4ea","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7c7ac736b50fa259ed1bdddc18d79523f07c0442","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/827de6bd2865b22aaabd554540def3b8a33018ab","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00352,"epssPercentile":0.28795,"ingestedAt":"2026-09-17T16:21:47.892Z","slug":"CVE-2026-90091","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":44,"depthScoreParts":{"impact":44,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":207111,"id":"CVE-2026-90091","ts":1789757332846,"field":"cvss","old":null,"new":"8"},{"seq":207110,"id":"CVE-2026-90091","ts":1789757332846,"field":"severity","old":"none","new":"high"}]}