Bug 2400059 (CVE-2025-39795)

Summary: CVE-2025-39795 kernel: block: avoid possible overflow for chunk_sectors check in blk_stack_limits()
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 2025-09-29 07:01:50 UTC 
In the Linux kernel, the following vulnerability has been resolved:

block: avoid possible overflow for chunk_sectors check in blk_stack_limits()

In blk_stack_limits(), we check that the t->chunk_sectors value is a
multiple of the t->physical_block_size value.

However, by finding the chunk_sectors value in bytes, we may overflow
the unsigned int which holds chunk_sectors, so change the check to be
based on sectors.
Comment 1 Jon Moroney 2025-09-29 18:10:28 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091223-CVE-2025-39795-c418@gregkh/T