Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.188, 6.6.157, 6.12.110, 6.18.52, 7.2, and 1 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From b39298044e5534612511a2ff5de03ba5f6e7a820 · fixed in 827de6bd2865b22aaabd554540def3b8a33018ab; From 8c37e4338c801ebb8cee52436c01c41e009f6e87 · fixed in 7c7ac736b50fa259ed1bdddc18d79523f07c0442; From 84e718b6a814edc84159361f9f454a4e92ae91ae · fixed in 4f8c63fe0097c9f6ea34409f82f79b3894903d91; From 36da806f7fbaee56ad9e81859deec203f9728700 · fixed in 61d5ddbd524c715b224cbe7e9f01da4e05098b19; From 6fef032af0092ed5ccb767239a9ac1bc38c08a40 · fixed in 32a7bc6e93be36b37fe61f351d312d358195bd61; From 6fef032af0092ed5ccb767239a9ac1bc38c08a40 · fixed in 66d6ef18548ae6d7dd452b84115fc82c0a73a4ea; From 6.1.178 · fixed in 6.1.188; From 6.6.145 · fixed in 6.6.157; From 6.12.97 · fixed in 6.12.110; From 6.18.40 · fixed in 6.18.52; From 7.1.5 · fixed in 7.2
- Linux Linux
7.2
- KernelLinux
fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6