CVE-2026-74539 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: lock sk in iso_sock_getname
Accessing iso_pi(sk)->conn requires lock_sock, which is not held here.
Fix by adding the lock/release.
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Analysis
by VulDB Data Team • 08/16/2026
This vulnerability exists within the linux kernel's bluetooth subsystem specifically affecting the iso socket implementation. The issue stems from a missing synchronization mechanism during socket name retrieval operations. When the iso_sock_getname function attempts to access the iso_pi(sk)->conn structure, it fails to acquire the necessary socket lock that protects this critical data structure. This represents a classic race condition vulnerability where concurrent access to shared kernel memory without proper locking can lead to inconsistent or corrupted data states.
The technical flaw manifests as an improper locking sequence in the bluetooth iso socket subsystem where the iso_sock_getname function directly references iso_pi(sk)->conn without first acquiring the socket lock through lock_sock(). This violates fundamental kernel synchronization principles and creates opportunities for data races between concurrent threads attempting to access the same socket connection structure. The vulnerability specifically affects the iso (isochronous) socket implementation within the bluetooth subsystem, which handles high-bandwidth real-time data transfers.
The operational impact of this vulnerability extends beyond simple data corruption to potentially enable privilege escalation or system instability. An attacker with local access could exploit this race condition to manipulate socket connection states, potentially leading to denial of service conditions or unauthorized data access within the bluetooth subsystem. The flaw particularly affects systems running linux kernels with active bluetooth iso connections where multiple threads might simultaneously attempt to query socket information while other operations modify the underlying connection structure.
Mitigation strategies should focus on implementing proper locking mechanisms as indicated in the fix. The solution requires adding lock_sock() before accessing iso_pi(sk)->conn and corresponding release_sock() calls afterward, ensuring atomic access to the shared data structure. This approach aligns with common security practices outlined in the linux kernel security documentation and follows established patterns for protecting shared kernel resources. System administrators should prioritize applying the relevant kernel patches that implement this locking fix to prevent exploitation of this race condition vulnerability.
This vulnerability maps directly to CWE-362, which describes concurrent execution using shared resource without proper synchronization mechanisms. The issue also relates to ATT&CK technique T1068, which covers local privilege escalation through kernel vulnerabilities. The fix demonstrates the importance of following kernel security best practices as outlined in the linux kernel documentation regarding proper locking and resource management in multi-threaded environments. Organizations should verify their kernel versions against the published patches and ensure all bluetooth subsystem components are updated to prevent exploitation of this race condition that could compromise system integrity and availability.