Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3 block bdev_mark_dead resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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4.2$0-$5k1.55-

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3. The affected element is the function bdev_mark_dead of the component block. This manipulation causes resource consumption. This vulnerability is registered as CVE-2026-64326. The attack needs to be launched locally. No exploit is available.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3 and classified as problematic. Affected by this vulnerability is the function bdev_mark_dead of the component block. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

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).

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-64326 since 07/19/2026. The exploitation appears to be easy. An attack has to be approached locally. The exploitation requires an enhanced level of successful authentication. Technical details are known, but no exploit is available.

Upgrading to version 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch d6998ddd507c81e3829489a6ead23f17f5acb7fe/f41cf35ee2a1e31374b3f54e7579c55153506e70/9818bcae3c0ca1dde4b9a334125c46676e0a9b29/aa4c4a9315764b2b7a7182e72cc5ea87520436b4/49f06cff50a4ccf3b7a1a662ceb892b3b21a527a is able to eliminate this problem.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: d6998ddd507c81e3829489a6ead23f17f5acb7fe/f41cf35ee2a1e31374b3f54e7579c55153506e70/9818bcae3c0ca1dde4b9a334125c46676e0a9b29/aa4c4a9315764b2b7a7182e72cc5ea87520436b4/49f06cff50a4ccf3b7a1a662ceb892b3b21a527a

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64326 (🔒)
GCVE (CVE): GCVE-0-2026-64326
GCVE (VulDB): GCVE-100-383125

Entryinfo

Created: 07/25/2026 15:36
Changes: 07/25/2026 15:36 (59)
Complete: 🔍
Cache ID: 216::103

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