CVE-2026-53059 dm log: fix out-of-bounds write due to region_count overflow
An integer overflow in the Linux kernel device-mapper log allows out-of-bounds writes, potentially leading to code execution or system crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53059?
CVE-2026-53059 is a high-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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 \ core 2 2 nosync 2 /dev/mapper/bigzero 0 \ /dev/mapper/bigzero 0'
The status output confirms the truncation (sync_count=1 instead of 4294967297, because 0x100000001 was truncated to 1):
$ dmsetup status mymirror 0 8589934594 mirror 2 254:1 254:1 1/4294967297 ...
This leads to a kernel crash in core_in_sync:
BUG: scheduling while atomic: (udev-worker)/9150/0x00000000 RIP: 0010:core_in_sync+0x14/0x30 [dm_log] CR2: 0000000000000008 Fixing recursive fault but reboot is needed!
Fix by widening the local region_count to sector_t and adding an explicit overflow check before the value is assigned to lc->region_count.
Which versions are affected by CVE-2026-53059?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53059?
Apply the vendor's patch.
Is CVE-2026-53059 being exploited?
There is no known exploitation of CVE-2026-53059 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53059, DEBIAN-CVE-2026-53059, GHSA-vj88-ppr4-hj46, ROOT-OS-DEBIAN-11-CVE-2026-53059, ROOT-OS-DEBIAN-12-CVE-2026-53059, ROOT-OS-UBUNTU-2204-CVE-2026-53059 and 2 more.