CVE-2026-72105

Technical Description

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

dm-log: fix a bitset_size overflow on 32bit machines

Commit c20e36b7631d ("dm log: fix out-of-bounds write due to

region_count overflow") made sure that region_count could fit in an

unsigned int. But the bitmap memory isn't allocated based on

region_count. It uses bitset_size (a size_t variable). The first step of

calculating bitset_size is to set it to region_count, rounded up to a

multiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG

smaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit

architecture, this will make bitset_size wrap around to 0 and fail,

despite region_count being valid.

Since bitset_size gets divided by 8, it can hold any valid region_count.

It just needs a special case to handle the rollover. If it is 0, the

value rolled over, and bitset size should be set to the number of bytes

needed to hold 2^32 bits.

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