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CVE PROGRAM SOURCE RECORD8.0 High

CVE-2026-90091

Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan

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Status
Published
Published
Updated
Assigning organization
Linux

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b39298044e5534612511a2ff5de03ba5f6e7a820 to < 827de6bd2865b22aaabd554540def3b8a33018abaffected
  • 8c37e4338c801ebb8cee52436c01c41e009f6e87 to < 7c7ac736b50fa259ed1bdddc18d79523f07c0442affected
  • 84e718b6a814edc84159361f9f454a4e92ae91ae to < 4f8c63fe0097c9f6ea34409f82f79b3894903d91affected
  • 36da806f7fbaee56ad9e81859deec203f9728700 to < 61d5ddbd524c715b224cbe7e9f01da4e05098b19affected
  • 6fef032af0092ed5ccb767239a9ac1bc38c08a40 to < 32a7bc6e93be36b37fe61f351d312d358195bd61affected
  • 6fef032af0092ed5ccb767239a9ac1bc38c08a40 to < 66d6ef18548ae6d7dd452b84115fc82c0a73a4eaaffected
  • 733e76e74e406c1d1ddc7369420dd8a47f48bb8aaffected
  • 6.1.178 to < 6.1.188affected
  • 6.6.145 to < 6.6.157affected
  • 6.12.97 to < 6.12.110affected
  • 6.18.40 to < 6.18.52affected
  • 7.1.5 to < 7.2affected

Linux Linux

Default version status: affected

  • 7.2affected
  • 0 to < 7.2unaffected
  • 6.1.188 to ≤ 6.1.*unaffected
  • 6.6.157 to ≤ 6.6.*unaffected
  • 6.12.110 to ≤ 6.12.*unaffected
  • 6.18.52 to ≤ 6.18.*unaffected
  • 7.2.6 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References