CVE-2026-93829

Summary

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix races in cifsd thread creation

The cifsd demultiplex thread can run and access tcp_ses before the parent thread has finished populating tcp_ses, which the worker thread accesses locklessly.

Also, the kthread_run macro may start the thread before returning the thread pointer. Because the pointer is part of the structure that the thread can access, if the kernel is preempted after the thread is spawned, but before the thread pointer is populated and the thread attempts to exit, it will sleep, waiting for a SIGKILL signal.

Fix this by moving creation of the thread to after all of tcp_ses'es fields are populated, and spawning the thread last, using a split kthread_create/wake_up_process logic.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxaaf737adb6937339494d5a7111f0433cd9676db8 < ee8f811cbac56ffb738b3a73671a9e75b0f56e99affected
LinuxLinuxaaf737adb6937339494d5a7111f0433cd9676db8 < 0eee1e6cddd1d9ce14da06e0238ca8d3362dec90affected
LinuxLinuxaaf737adb6937339494d5a7111f0433cd9676db8 < e8a5cf2ff5a13fefb228f2069e29dd7d8e37185daffected
LinuxLinux2.6.22affected
LinuxLinux0 < 2.6.22unaffected
LinuxLinux6.12.111 <= 6.12.*unaffected
LinuxLinux6.18.53 <= 6.18.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References