CVE-2026-53059

/// Technical description

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

dm log: fix out-of-bounds write due to region_count overflow

The local variable region_count in create_log_context() is declared as

unsigned int (32-bit), but dm_sector_div_up() returns sector_t (64-bit).

When a device-mapper target has a sufficiently large ti->len with a small

region_size, the division result can exceed UINT_MAX. The truncated

value is then used to calculate bitset_size, causing clean_bits,

sync_bits, and recovering_bits to be allocated far smaller than needed

for the actual number of regions.

Subsequent log operations (log_set_bit, log_clear_bit, log_test_bit) use

region indices derived from the full untruncated region space, causing

out-of-bounds writes to kernel heap memory allocated by vmalloc.

This can be reproduced by creating a mirror target whose region_count

overflows 32 bits:

dmsetup create bigzero --table '0 8589934594 zero'

dmsetup create mymirror --table '0 8589934594 mirror \

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References