CVE-2026-64326 Affecting kernel-azure-vdso package, versions <6.12.0-160000.38.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.16% (6th percentile)

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  • Snyk IDSNYK-SLES1600-KERNELAZUREVDSO-20316748
  • published30 Sept 2026
  • disclosed22 Sept 2026

Introduced: 22 Sep 2026

NewCVE-2026-64326  (opens in a new tab)

How to fix?

Upgrade SLES:16.0.0 kernel-azure-vdso to version 6.12.0-160000.38.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-azure-vdso package and not the kernel-azure-vdso package as distributed by SLES. See How to fix? for SLES:16.0.0 relevant fixed versions and status.

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).

CVSS Base Scores

version 3.1