CVE-2025-39795: block: avoid possible overflow for chunk_sectors check in blk_stack_limits()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-12 · updated 2026-10-19
Weakness: CWE-674

Description

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.

Affected products

Debian Linux: 11.0
Linux kernel: from 5.10 before 5.10.241; from 5.11 before 5.15.190; from 5.16 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.43; from 6.13 before 6.15.11 — fixed in 5.10.241, 5.15.190, 6.1.149, 6.12.43, 6.15.11, 6.16.2

How to fix

Upgrade to a fixed version: Linux kernel 5.10.241, 5.15.190, 6.1.149, 6.12.43. Check the vendor advisory for mitigations.

References

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