# 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.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 4 Sep 2026
- **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, ROOT-OS-UBUNTU-2404-CVE-2026-53059, UBUNTU-CVE-2026-53059

## 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-53059?

It affects 1 product.


Products: 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

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53059 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-53059 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53059/ (Markdown: https://insights.sbomify.com/CVE-2026-53059/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53059
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53059
- OSV: https://osv.dev/vulnerability/CVE-2026-53059

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53059/
Summaries are generated and may contain mistakes; the official description above is the record.