CVE-2026-64326
block: skip sync_blockdev() on surprise removal in bdev_mark_dead()
Description
In the Linux kernel, the following vulnerability has been resolved: block: skip sync_blockdev() on surprise removal in bdev_mark_dead() bdev_mark_dead()'s @surprise == true means the device is already gone. The filesystem callback fs_bdev_mark_dead() honours this and skips sync_filesystem(), but the bare block device path (no ->mark_dead op) lost its !surprise guard when the holder ->mark_dead callback was wired up (see Fixes), and now calls sync_blockdev() unconditionally, which can hang forever waiting on writeback that can no longer complete. syzkaller hit this via nvme_reset_work()'s "I/O queues lost" path: nvme_mark_namespaces_dead() -> blk_mark_disk_dead() -> bdev_mark_dead(bdev, true) -> sync_blockdev() blocks in folio_wait_writeback(), wedging the reset worker and every task waiting on it. Skip the sync on surprise removal, matching fs_bdev_mark_dead(); invalidate_bdev() still runs. Orderly removal (surprise == false) is unchanged. Found by FuzzNvme(Syzkaller with FEMU fuzzing framework).
INFO
Published Date :
July 25, 2026, 10:17 a.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest stable version.
- Apply the specific patch for the block subsystem.
- Ensure device removal handling is robust.
- Monitor system logs for I/O errors.
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-2026-64326.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64326 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-2026-64326
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-2026-64326 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64326 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
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'd6998ddd507c81e3829489a6ead23f17f5acb7fe', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'f41cf35ee2a1e31374b3f54e7579c55153506e70', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '9818bcae3c0ca1dde4b9a334125c46676e0a9b29', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'aa4c4a9315764b2b7a7182e72cc5ea87520436b4', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '49f06cff50a4ccf3b7a1a662ceb892b3b21a527a', 'versionType': 'git'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'd6998ddd507c81e3829489a6ead23f17f5acb7fe', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'f41cf35ee2a1e31374b3f54e7579c55153506e70', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '9818bcae3c0ca1dde4b9a334125c46676e0a9b29', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'aa4c4a9315764b2b7a7182e72cc5ea87520436b4', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '49f06cff50a4ccf3b7a1a662ceb892b3b21a527a', 'versionType': 'git'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 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': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'd6998ddd507c81e3829489a6ead23f17f5acb7fe', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'f41cf35ee2a1e31374b3f54e7579c55153506e70', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '9818bcae3c0ca1dde4b9a334125c46676e0a9b29', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': 'aa4c4a9315764b2b7a7182e72cc5ea87520436b4', 'versionType': 'git'}, {'status': 'affected', 'version': 'd8530de5a6e82be0ce17a5fdf727a394bcf6444c', 'lessThan': '49f06cff50a4ccf3b7a1a662ceb892b3b21a527a', 'versionType': 'git'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.6'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.6', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['block/bdev.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: block: skip sync_blockdev() on surprise removal in bdev_mark_dead() bdev_mark_dead()'s @surprise == true means the device is already gone. The filesystem callback fs_bdev_mark_dead() honours this and skips sync_filesystem(), but the bare block device path (no ->mark_dead op) lost its !surprise guard when the holder ->mark_dead callback was wired up (see Fixes), and now calls sync_blockdev() unconditionally, which can hang forever waiting on writeback that can no longer complete. syzkaller hit this via nvme_reset_work()'s "I/O queues lost" path: nvme_mark_namespaces_dead() -> blk_mark_disk_dead() -> bdev_mark_dead(bdev, true) -> sync_blockdev() blocks in folio_wait_writeback(), wedging the reset worker and every task waiting on it. Skip the sync on surprise removal, matching fs_bdev_mark_dead(); invalidate_bdev() still runs. Orderly removal (surprise == false) is unchanged. Found by FuzzNvme(Syzkaller with FEMU fuzzing framework). Added Reference https://git.kernel.org/stable/c/49f06cff50a4ccf3b7a1a662ceb892b3b21a527a Added Reference https://git.kernel.org/stable/c/9818bcae3c0ca1dde4b9a334125c46676e0a9b29 Added Reference https://git.kernel.org/stable/c/aa4c4a9315764b2b7a7182e72cc5ea87520436b4 Added Reference https://git.kernel.org/stable/c/d6998ddd507c81e3829489a6ead23f17f5acb7fe Added Reference https://git.kernel.org/stable/c/f41cf35ee2a1e31374b3f54e7579c55153506e70