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Linux KernelOperating system · Linux

CVE-2026-53059

HIGH · 7.8 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 5.10.258 / 5.15.209 or later.
See remediation →
80/100
Remediation priority · High
Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In Linux kernel's device-mapper log module, the local variable region_count (unsigned int, 32-bit) receives the result of dm_sector_div_up() which returns sector_t (64-bit). When a dm target has large ti->len with small region_size, the division can exceed UINT_MAX, causing truncation. This truncated value underallocates bitset arrays (clean_bits, sync_bits, recovering_bits), and subsequent log operations using untruncated region indices cause out-of-bounds writes to vmalloc-allocated kernel heap memory, leading to kernel crashes.

MitigationApply the upstream kernel patch widening region_count to sector_t with overflow checking. As a workaround, avoid creating device-mapper mirror targets with region_count exceeding 32-bit limits (e.g., ensure region_size is large enough relative to device size).

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.12.1, < 5.10.258>= 5.11, < 5.15.209>= 5.16, < 6.1.175>= 6.2, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10= 2.6.12

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if device-mapper mirror targets exist
    Run 'dmsetup status' or 'dmsetup table' to list active device-mapper devices. Look for devices with type 'mirror' in the target specification.
    Affected if No mirror targets are configured, the system is not affected by this vulnerability.
  2. Verify kernel version against affected range
    Run 'uname -r' or 'cat /proc/version' to obtain the running kernel version. Compare this version to the known affected and fixed versions for this CVE.
    Affected if The kernel version falls within the affected range and has not been patched, the system could be vulnerable.
  3. Identify mirror device parameters
    For each dm-mirror device, examine the target parameters: device size (ti->len) and region_size. Use 'dmsetup table <device_name>' to view the full target specification.
    Affected if The mirror device parameters cannot be retrieved, the check is inconclusive.
  4. Calculate region_count ratio
    Compute ti->len / region_size for each mirror target. The ti->len value is the device size in sectors. Region_size is specified in the mirror parameters. Compare the result against UINT_MAX (4294967295).
    Affected if The calculated region_count exceeds UINT_MAX, the system is vulnerable to the integer overflow described in this CVE.

A system is affected if it runs a vulnerable kernel version, has active dm-mirror targets configured, and any mirror target has a ti->len/region_size ratio that exceeds UINT_MAX, causing the integer overflow.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.10.258 / 5.15.209 / 6.1.175 or later
Fixed in 5.10.2585.15.2096.1.175
Interim mitigation

Apply the upstream kernel patch widening region_count to sector_t with overflow checking. As a workaround, avoid creating device-mapper mirror targets with region_count exceeding 32-bit limits (e.g., ensure region_size is large enough relative to device size).

Recommended fix High confidence

Linux kernel 5.10.258 / 5.15.209 / 6.1.175 / 6.6.141 (depending on your current branch)

  1. 1. Identify the currently running Linux kernel version using 'uname -r'
  2. 2. Determine which version branch your kernel falls into from the affected ranges: < 5.10.258, < 5.15.209, < 6.1.175, or < 6.6.141
  3. 3. For kernels in the 5.10.x branch: upgrade to kernel version 5.10.258 or later
  4. 4. For kernels in the 5.11-5.15.x branch: upgrade to kernel version 5.15.209 or later
  5. 5. For kernels in the 5.16-6.1.x branch: upgrade to kernel version 6.1.175 or later
  6. 6. For kernels in the 6.2-6.6.x branch: upgrade to kernel version 6.6.141 or later
  7. 7. After kernel upgrade, reboot the system to load the patched kernel
  8. 8. Verify the fix is applied by checking that the kernel version matches or exceeds the appropriate fixed release
Caveat Kernel upgrades may require recompiling out-of-tree modules; ensure compatible drivers and modules are available before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53059 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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