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Linux KernelOperating system · Linux

CVE-2026-53050

HIGH · 7.8 CVSS v3.1 Published 2026-06-24
Fix available
A fix is available. Upgrade to 4.20 / 5.5 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: quota: Fix race of dquot_scan_active() with quota deactivation dquot_scan_active() can race with quota deactivation in quota_release_workfn() like: CPU0 (quota_release_workfn) CPU1 (dquot_scan_active) ============================== ============================== spin_lock(&dq_list_lock); list_replace_init( &releasing_dquots, &rls_head); /* dquot X on rls_head, dq_count == 0, DQ_ACTIVE_B still set */ spin_unlock(&dq_list_lock); synchronize_srcu(&dquot_srcu); spin_lock(&dq_list_lock); list_for_each_entry(dquot, &inuse_list, dq_inuse) { /* finds dquot X */ dquot_active(X) -> true atomic_inc(&X->dq_count); } spin_unlock(&dq_list_lock); spin_lock(&dq_list_lock); dquot = list_first_entry(&rls_head); WARN_ON_ONCE(atomic_read(&dquot->dq_count)); The problem is not only a cosmetic one as under memory pressure the caller of dquot_scan_active() can end up working on freed dquot. Fix the problem by making sure the dquot is removed from releasing list when we acquire a reference to it.

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

A race condition in the Linux kernel's disk quota subsystem allows dquot_scan_active() to access a dquot structure that is simultaneously being released by quota_release_workfn(). The releasing dquot still has DQ_ACTIVE_B flag set while being removed from the active list, leading to a use-after-free vulnerability where the caller can work on a freed dquot under memory pressure.

MitigationUpdate the Linux kernel to the version containing the fix. The fix ensures proper synchronization by removing the dquot from the releasing list when acquiring a reference, preventing the race condition.

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:>= 4.19.297, < 4.20>= 5.4.259, < 5.5>= 5.10.199, < 5.10.258>= 5.15.136, < 5.15.209>= 6.1.59, < 6.1.175>= 6.5.8, < 6.6>= 6.6.1, < 6.6.141>= 6.7, < 6.12.91>= 6.13, < 6.18.33>= 6.19, < 7.0.10= 6.6

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. Identify your kernel version
    Run 'uname -r' or check /proc/version to obtain the running kernel version
    Affected if The kernel version is older than the patched version containing the fix for the dquot race condition (specific version varies by distribution; compare against your distribution's security advisories)
  2. Verify quota subsystem is enabled
    Check if quota support is built into or loaded for your system: look for 'quota' in /proc/filesystems, or check for /etc/fstab entries with 'usrquota' or 'grpquota' options, or run 'quotacheck -cu' to see if quota is actively used
    Affected if Quotas are enabled and in use on the system (the vulnerability only affects systems using disk quotas)
  3. Confirm the dquot module or code path is present
    Verify the kernel was built with CONFIG_QUOTA support: grep -i quota /boot/config-$(uname -r) or check /proc/config.gz if available
    Affected if CONFIG_QUOTA is set to 'y' or 'm' in the kernel configuration (vulnerable code path exists)
  4. Check for active quota usage
    Run 'quota -u <user>' or 'quota -g <group>' to see if quota accounting is active; also check 'repquota -a' to list users with quota usage
    Affected if There are actively tracked quotas (the race condition occurs during active quota release operations)
  5. Review kernel dquot source for the fix
    Inspect the kernel source code if accessible: look for the synchronized removal from the releasing list in dquot_scan_active() and quota_release_workfn() - the fix should show __list_del_entry or equivalent protection before reference acquisition
    Affected if The source code shows the vulnerable pattern where reference acquisition happens before list removal (requires source inspection)
  6. Check distribution security advisories
    Consult your Linux distribution's CVE database or security mailing list for announcements regarding this specific CVE
    Affected if Your distribution has issued a security advisory confirming your kernel version is affected

A system is affected if it runs a kernel version prior to the patched release, has CONFIG_QUOTA enabled, and actively uses disk quotas - the race condition occurs in the dquot reference handling during quota release operations.

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 4.20 / 5.5 / 5.10.258 or later
Fixed in 4.205.55.10.258
Interim mitigation

Update the Linux kernel to the version containing the fix. The fix ensures proper synchronization by removing the dquot from the releasing list when acquiring a reference, preventing the race condition.

Recommended fix Moderate confidence

Any stable Linux kernel version released after the fix was merged (check git.kernel.org for the specific commit)

  1. Upgrade the Linux kernel to a version that includes the fix for CVE-2026-53050
  2. The fix was merged into the Linux kernel source tree - obtain a kernel version that includes the commit resolving this quota race condition
  3. After kernel upgrade, verify the system is running the new kernel version using 'uname -r'
  4. Reboot the system to ensure the new kernel is loaded
Caveat Kernel upgrades may require system reboot and could have compatibility implications with certain drivers or modules

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

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing6.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,120
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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-2026-53050 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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