CVE-2026-64017
blk-mq: pop cached request if it is usable
Description
In the Linux kernel, the following vulnerability has been resolved: blk-mq: pop cached request if it is usable When submitting a bio to blk-mq, if the task should sleep after peeking a cached request, but before it pops it, the plug flushes and calls blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a use-after-free bug. Fix this by popping the cached request before any possible blocking calls if it is suitable for use. Popping this request first holds a queue reference, so avoid any serialization races with queue freezes and can safely proceed with dispatching that request to the driver. This potentially increases a timing window from when a driver wants to freeze its queue to when requests stop being dispatched. That scenario is off the fast path though, and drivers need to appropriately handle requests during a freeze request anyway. The downside is the popped element needs to be individually freed when we performed a bio plug merge. The cached request would have had to be freed later anyway, but this patch does it inline with building the plug list instead of after flushing it.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 30, 2026, 2:59 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest stable version.
- Apply the patch for the blk-mq request handling.
- Rebuild and deploy the kernel with the fix.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64017.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/388468f7e7d1eab092cf2a39fdfb502e52019ec6 | |
| https://git.kernel.org/stable/c/dc278e9bf2b9513a763353e6b9cc21e0f532954e |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64017 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64017
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64017 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64017 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'b0077e269f6c152e807fdac90b58caf012cdbaab', 'lessThan': '388468f7e7d1eab092cf2a39fdfb502e52019ec6', 'versionType': 'git'}, {'status': 'affected', 'version': 'b0077e269f6c152e807fdac90b58caf012cdbaab', 'lessThan': 'dc278e9bf2b9513a763353e6b9cc21e0f532954e', 'versionType': 'git'}, {'status': 'affected', 'version': 'b5c8e0ff76d10f6bf70a7237678f27c20cf59bc9', 'versionType': 'git'}, {'status': 'affected', 'version': 'e9c309ded295b7f8849097d71ae231456ca79f78', 'versionType': 'git'}, {'status': 'affected', 'version': 'b80056bd75a16e4550873ecefe12bc8fd190b1cf', 'versionType': 'git'}, {'status': 'affected', 'version': '33cf52b6e53a6aa55883aa7fb9ceffceff8488a6', 'versionType': 'git'}, {'status': 'affected', 'version': '8b6075046470c8756242dfe3fd058813636f69a3', 'versionType': 'git'}, {'status': 'affected', 'version': '6.1.72', 'lessThan': '6.2', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.5.13', 'lessThan': '6.6', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.6.3', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.1.75', 'lessThan': '6.2', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.6.14', 'lessThan': '6.7', 'versionType': 'semver'}], 'programFiles': ['block/blk-mq.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.0.11', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['block/blk-mq.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: blk-mq: pop cached request if it is usable When submitting a bio to blk-mq, if the task should sleep after peeking a cached request, but before it pops it, the plug flushes and calls blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a use-after-free bug. Fix this by popping the cached request before any possible blocking calls if it is suitable for use. Popping this request first holds a queue reference, so avoid any serialization races with queue freezes and can safely proceed with dispatching that request to the driver. This potentially increases a timing window from when a driver wants to freeze its queue to when requests stop being dispatched. That scenario is off the fast path though, and drivers need to appropriately handle requests during a freeze request anyway. The downside is the popped element needs to be individually freed when we performed a bio plug merge. The cached request would have had to be freed later anyway, but this patch does it inline with building the plug list instead of after flushing it. Added Reference https://git.kernel.org/stable/c/388468f7e7d1eab092cf2a39fdfb502e52019ec6 Added Reference https://git.kernel.org/stable/c/dc278e9bf2b9513a763353e6b9cc21e0f532954e