In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close()… (CVE-2026-63945)
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.
AI Analysis
Technical Summary
The Linux kernel Bluetooth ISO socket code had a race condition where iso_sock_clear_timer() read iso_pi(sk)->conn twice without holding the socket lock. Concurrent execution of iso_conn_del() under the socket lock could set iso_pi(sk)->conn to NULL, causing iso_sock_clear_timer() to dereference a NULL pointer or use freed memory. The fix involved moving iso_sock_clear_timer() inside the lock_sock()/release_sock() critical section to ensure serialization and prevent the race.
Potential Impact
This vulnerability could lead to kernel NULL pointer dereference or use-after-free conditions, potentially causing kernel crashes or instability. There is no indication of known exploits in the wild. The impact is limited to denial of service or system instability rather than privilege escalation or code execution based on the provided data.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability was resolved by serializing iso_sock_clear_timer() with the socket lock in the Linux kernel source code. Users should apply the official Linux kernel updates once available to address this issue.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close()… (CVE-2026-63945)
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.
CVSS v3.1
Score 7.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel Bluetooth ISO socket code had a race condition where iso_sock_clear_timer() read iso_pi(sk)->conn twice without holding the socket lock. Concurrent execution of iso_conn_del() under the socket lock could set iso_pi(sk)->conn to NULL, causing iso_sock_clear_timer() to dereference a NULL pointer or use freed memory. The fix involved moving iso_sock_clear_timer() inside the lock_sock()/release_sock() critical section to ensure serialization and prevent the race.
Potential Impact
This vulnerability could lead to kernel NULL pointer dereference or use-after-free conditions, potentially causing kernel crashes or instability. There is no indication of known exploits in the wild. The impact is limited to denial of service or system instability rather than privilege escalation or code execution based on the provided data.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability was resolved by serializing iso_sock_clear_timer() with the socket lock in the Linux kernel source code. Users should apply the official Linux kernel updates once available to address this issue.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-85m8-5mhx-q797
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63945"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5d27aa2a4a8d598912ebd2
Added to database: 07/19/2026, 19:38:18 UTC
Last enriched: 07/19/2026, 20:05:42 UTC
Last updated: 09/02/2026, 22:52:13 UTC
Views: 60
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