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CVE-2026-46023 Linux CVE debrief

An integer overflow vulnerability in the Linux kernel's device mapper (dm) mirror subsystem could allow an attacker with privileges to configure device mapper tables to trigger out-of-bounds memory reads. The flaw exists in create_dirty_log() where param_count is added to 2 before validation against argc; when param_count is near UINT_MAX, the unsigned addition wraps to a small value, bypassing bounds checks and passing the overflowed value to dm_dirty_log_create(). The fix validates param_count against argc - 2 before performing the addition, matching the pattern used by parse_features() in the same file.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-06-16
Advisory published
2026-05-27
Advisory updated
2026-06-16

Who should care

Linux system administrators using device mapper mirroring (dm-mirror); security teams monitoring kernel memory safety vulnerabilities; organizations with strict privilege separation requirements for storage subsystem configuration

Technical summary

The create_dirty_log() function in drivers/md/dm-mirror.c calculates *args_used = 2 + param_count before validating param_count against argc. With param_count near UINT_MAX, unsigned integer wraparound produces a small *args_used value, causing the argc < *args_used check to pass incorrectly. The overflowed param_count propagates to dm_dirty_log_create() as argc, leading to out-of-bounds argv array access. The fix reorders validation: param_count is checked against argc - 2 (safe since argc >= 2 is guaranteed) before the addition, preventing the overflow condition.

Defensive priority

medium

Recommended defensive actions

  • Apply kernel updates from stable branches when available (commits referenced in sourceItem metadata)
  • Restrict device mapper configuration privileges to trusted administrative accounts
  • Monitor for unusual device mapper table configurations in audit logs
  • Validate that systems using dm-mirror are running patched kernel versions

Evidence notes

CVE published 2026-05-27. Kernel.org stable branch commits provided as references. No CVSS score assigned by NVD at time of disclosure; status 'Awaiting Analysis'. Vendor identified as Kernel with low confidence per source metadata.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-46023 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-46023

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-46023 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-46023

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/17a08791d428885d00e510864283a7b839792368

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/35f6b3281efd44d19110574663bc17a610bc73b9

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/47dad9eea75d33212d3d2cea10e7ed6a1bfc0713

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/4c788c6f921b22f9b6c3f316c4a071c05683e7de

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/87c99a50e0fdc68a5b9b52a94d49452cd3ff02ca

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.