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.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Thu, 24 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | smb: client: fix races in cifsd thread creation | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T16:03:11.886Z
Reserved: 2026-09-18T17:59:28.793Z
Link: CVE-2026-93829
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-24T17:17:16.630
Modified: 2026-09-24T17:17:16.630
Link: CVE-2026-93829
Redhat
No data.
OpenCVE Enrichment
No data.
No weakness.