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Review reviewHigh

CVE-2026-43178

Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6

In the Linux kernel, the following vulnerability has been resolved: procfs: fix possible double mmput() in do_procmap_query() When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf.

CVSS
7.8
EPSS
0.13%
3.19% percentile
CISA KEV
Not listed
Published
2026.05.06
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.13%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: procfs: fix possible double mmput() in do_procmap_query() When user provides incorrectly sized buffer for build ID for PROCMAP_QUERY we return with -ENAMETOOLONG error. After recent changes this condition happens later, after we unlocked mmap_lock/per-VMA lock and did mmput(), so original goto out is now wrong and will double-mmput() mm_struct. Fix by jumping further to clean up only vm_file and name_buf.

Affected product and versions

Product
Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6
Affected versions
>= b9b97e6aeb534315f9646b2090d1a5024c6a4e82 < f9fe092084cd04deea18747f58a2304026e76aaa, >= cbc03ce3e6ce7e21214c3f02218213574c1a2d08 < 8adaff87db143583e08eec4f4e7788f1ef8af94d, >= b5cbacd7f86f4f62b8813688c8e73be94e8e1951 < 90f5e87c9b75833b9ef3a4415b92c0247f28ab2f, >= b5cbacd7f86f4f62b8813688c8e73be94e8e1951 < 61dc9f776705d6db6847c101b98fa4f0e9eb6fa3, >= 6.12.70 < 6.12.75, >= 6.18.10 < 6.18.16, >= 6.19, >= 6.19.1 < 6.19.6, 6.19
Fixed versions
6.12.75, 6.18.16, 6.19.6

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-1341, CWE-415