{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64326", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.780Z", "datePublished": "2026-07-25T08:49:54.327Z", "dateUpdated": "2026-07-25T08:49:54.327Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-25T08:49:54.327Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblock: skip sync_blockdev() on surprise removal in bdev_mark_dead()\n\nbdev_mark_dead()'s @surprise == true means the device is already gone.\nThe filesystem callback fs_bdev_mark_dead() honours this and skips\nsync_filesystem(), but the bare block device path (no ->mark_dead op)\nlost its !surprise guard when the holder ->mark_dead callback was wired\nup (see Fixes), and now calls sync_blockdev() unconditionally, which can\nhang forever waiting on writeback that can no longer complete.\n\nsyzkaller hit this via nvme_reset_work()'s \"I/O queues lost\" path:\nnvme_mark_namespaces_dead() -> blk_mark_disk_dead() ->\nbdev_mark_dead(bdev, true) -> sync_blockdev() blocks in\nfolio_wait_writeback(), wedging the reset worker and every task waiting\non it.\n\nSkip the sync on surprise removal, matching fs_bdev_mark_dead();\ninvalidate_bdev() still runs. Orderly removal (surprise == false) is\nunchanged.\n\nFound by FuzzNvme(Syzkaller with FEMU fuzzing framework)."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["block/bdev.c"], "versions": [{"version": "d8530de5a6e82be0ce17a5fdf727a394bcf6444c", "lessThan": "d6998ddd507c81e3829489a6ead23f17f5acb7fe", "status": "affected", "versionType": "git"}, {"version": "d8530de5a6e82be0ce17a5fdf727a394bcf6444c", "lessThan": "f41cf35ee2a1e31374b3f54e7579c55153506e70", "status": "affected", "versionType": "git"}, {"version": "d8530de5a6e82be0ce17a5fdf727a394bcf6444c", "lessThan": "9818bcae3c0ca1dde4b9a334125c46676e0a9b29", "status": "affected", "versionType": "git"}, {"version": "d8530de5a6e82be0ce17a5fdf727a394bcf6444c", "lessThan": "aa4c4a9315764b2b7a7182e72cc5ea87520436b4", "status": "affected", "versionType": "git"}, {"version": "d8530de5a6e82be0ce17a5fdf727a394bcf6444c", "lessThan": "49f06cff50a4ccf3b7a1a662ceb892b3b21a527a", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["block/bdev.c"], "versions": [{"version": "6.6", "status": "affected"}, {"version": "0", "lessThan": "6.6", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.12.96"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6", "versionEndExcluding": "7.2-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/d6998ddd507c81e3829489a6ead23f17f5acb7fe"}, {"url": "https://git.kernel.org/stable/c/f41cf35ee2a1e31374b3f54e7579c55153506e70"}, {"url": "https://git.kernel.org/stable/c/9818bcae3c0ca1dde4b9a334125c46676e0a9b29"}, {"url": "https://git.kernel.org/stable/c/aa4c4a9315764b2b7a7182e72cc5ea87520436b4"}, {"url": "https://git.kernel.org/stable/c/49f06cff50a4ccf3b7a1a662ceb892b3b21a527a"}], "title": "block: skip sync_blockdev() on surprise removal in bdev_mark_dead()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{}

{"bugzilla": {"description": "kernel: block: skip sync_blockdev() on surprise removal in bdev_mark_dead()", "id": "2507027", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2507027"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-390", "details": ["A flaw was found in the Linux kernel's block device handling. When a block device is unexpectedly removed, the `bdev_mark_dead()` function can unconditionally attempt to synchronize the device, even if it is no longer present. This can lead to a system hang, effectively causing a Denial of Service (DoS), as the system waits indefinitely for writeback operations that cannot complete. This vulnerability can be triggered by a local user or process interacting with block devices during surprise removal events."], "name": "CVE-2026-64326", "public_date": "2026-07-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64326\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64326\nhttps://lore.kernel.org/linux-cve-announce/2026072512-CVE-2026-64326-8454@gregkh/T"], "threat_severity": "Moderate"}