CVE-2026-64326 (GCVE-0-2026-64326)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:53
VLAI
Title
block: skip sync_blockdev() on surprise removal in bdev_mark_dead()
Summary
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).
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: d8530de5a6e82be0ce17a5fdf727a394bcf6444c , < d6998ddd507c81e3829489a6ead23f17f5acb7fe (git)
Affected: d8530de5a6e82be0ce17a5fdf727a394bcf6444c , < f41cf35ee2a1e31374b3f54e7579c55153506e70 (git)
Affected: d8530de5a6e82be0ce17a5fdf727a394bcf6444c , < 9818bcae3c0ca1dde4b9a334125c46676e0a9b29 (git)
Affected: d8530de5a6e82be0ce17a5fdf727a394bcf6444c , < aa4c4a9315764b2b7a7182e72cc5ea87520436b4 (git)
Affected: d8530de5a6e82be0ce17a5fdf727a394bcf6444c , < 49f06cff50a4ccf3b7a1a662ceb892b3b21a527a (git)
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Linux Linux Affected: 6.6
Unaffected: 0 , < 6.6 (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.96 , ≤ 6.12.* (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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}



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