Bug 2429106 (CVE-2025-68786)

Summary: CVE-2025-68786 kernel: ksmbd: skip lock-range check on equal size to avoid size==0 underflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2026-01-13 16:07:08 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ksmbd: skip lock-range check on equal size to avoid size==0 underflow

When size equals the current i_size (including 0), the code used to call
check_lock_range(filp, i_size, size - 1, WRITE), which computes `size - 1`
and can underflow for size==0. Skip the equal case.
Comment 1 Jon Moroney 2026-01-14 22:57:12 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026011303-CVE-2025-68786-d145@gregkh/T