CVE-2026-63945 Details
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_clear_timer() if (conn != NULL) ... lock_sock(sk) iso_chan_del() iso_pi(sk)->conn = NULL cancel_delayed_work(conn) /* NULL deref or UAF */ iso_pi(sk)->conn is not stable across the unlock window, causing a NULL pointer dereference or use-after-free. Serialize iso_sock_clear_timer() with the socket lock by moving it inside lock_sock()/release_sock(), matching the pattern used in iso_conn_del() and all other call sites.
A vulnerability in the Linux kernel's handling of Bluetooth ISO sockets can lead to a null pointer dereference or a use-after-free condition. This issue arises because the function 'iso_sock_close()' calls 'iso_sock_clear_timer()' before acquiring the necessary socket lock. 'iso_sock_clear_timer()' accesses the connection information twice without the socket lock, creating a race condition. Meanwhile, 'iso_conn_del()' operates under the socket lock and can nullify the connection reference, potentially dropping the last connection reference. The vulnerability has been addressed by synchronizing 'iso_sock_clear_timer()' with the socket lock, aligning it with the practices used in other related functions.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for upgrading the Linux kernel can be found in the official Linux documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
No affected product data is available for this CVE.
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 20, 2026 | CVE Modified | kernel.org |
| Jul 19, 2026 | New CVE Received | kernel.org |