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Linux KernelOperating system · Linux

CVE-2026-53064

MEDIUM · 5.5 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 →
57/100
Remediation priority · Elevated
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 cache: fix null-deref with concurrent writes in passthrough mode In passthrough mode, when dm-cache starts to invalidate a cache entry and bio prison cell lock fails due to concurrent write to the same cached block, mg->cell remains NULL. The error path in invalidate_complete() attempts to unlock and free the cell unconditionally, causing a NULL pointer dereference: KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 134 Comm: fio Not tainted 6.19.0-rc7 #3 PREEMPT RIP: 0010:dm_cell_unlock_v2+0x3f/0x210 <snip> Call Trace: invalidate_complete+0xef/0x430 map_bio+0x130f/0x1a10 cache_map+0x320/0x6b0 __map_bio+0x458/0x510 dm_submit_bio+0x40e/0x16d0 __submit_bio+0x419/0x870 <snip> Reproduce steps: 1. Create a cache device dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 262144 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 262144 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. Promote the first data block into cache fio --filename=/dev/mapper/cache --name=populate --rw=write --bs=4k \ --direct=1 --size=64k 3. Reload the cache into passthrough mode dmsetup suspend cache dmsetup reload cache --table "0 262144 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 passthrough smq 0" dmsetup resume cache 4. Write to the first cached block concurrently fio --filename=/dev/mapper/cache --name test --rw=randwrite --bs=4k \ --randrepeat=0 --direct=1 --numjobs=2 --size 64k Fix by checking if mg->cell is valid before attempting to unlock 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

In Linux kernel's dm-cache device mapper, passthrough mode contains a NULL pointer dereference. When invalidating cache entries concurrently with writes, the bio prison cell lock can fail leaving mg->cell as NULL. The error path in invalidate_complete() unconditionally attempts to unlock this NULL cell, causing a kernel crash.

MitigationApply the kernel patch adding a NULL check for mg->cell before attempting unlock operations in invalidate_complete(). Rebuild and deploy the fixed kernel/module.

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:>= 4.12, < 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

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 kernel version
    Run `uname -r` or `cat /proc/version` to get the running kernel version
    Affected if The kernel version falls within any of these ranges: >= 4.12 and < 5.10.258; >= 5.11 and < 5.15.209; >= 5.16 and < 6.1.175; >= 6.2 and < 6.6.141; >= 6.7 and < 6.12.91; >= 6.13 and < 6.18.33; >= 6.19 and < 7.0.10
  2. Verify dm-cache module availability
    Check if the dm-cache target is available in the device-mapper by running `dmsetup targets | grep cache`
    Affected if The cache target is available (indicating dm-cache support is compiled in or loaded)
  3. Identify active dm-cache devices
    Run `dmsetup status` or `dmsetup table` and look for devices with type 'cache'
    Affected if Any active dm-cache devices exist in the system
  4. Check if cache devices use passthrough mode
    For each dm-cache device found, examine the cache policy and mode using `dmsetup status <device_name>` and look for 'passthrough' or 'p' in the policy flags
    Affected if Any dm-cache device is configured with passthrough mode enabled (this is the specific configuration required for the vulnerable code path to be exercised)

The system is affected if the kernel version is within the affected ranges AND dm-cache is actively used with passthrough mode enabled, as the vulnerability only triggers in that specific configuration path.

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 kernel patch adding a NULL check for mg->cell before attempting unlock operations in invalidate_complete(). Rebuild and deploy the fixed kernel/module.

Recommended fix High confidence

5.10.258, 5.15.209, 6.1.175, or 6.6.141 (depending on your current branch)

  1. Identify the currently running Linux kernel version using 'uname -r'
  2. Determine which version branch your kernel is based on (e.g., 5.10.x, 5.15.x, 6.1.x, or 6.6.x)
  3. Upgrade to a kernel version >= 5.10.258 if on the 5.10 branch
  4. Upgrade to a kernel version >= 5.15.209 if on the 5.15 branch
  5. Upgrade to a kernel version >= 6.1.175 if on the 6.1 branch
  6. Upgrade to a kernel version >= 6.6.141 if on the 6.6 branch
  7. Reboot the system to load the patched kernel
  8. Verify the fix is applied by checking the kernel version matches or exceeds the appropriate fixed version
Caveat Kernel upgrades may require rebooting services; ensure compatibility with other system components 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
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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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-2026-53064 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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