{"cve":"CVE-2026-64326","nvd":{"published":"2026-07-25T10:17:14.207","modified":"2026-09-04T14:51:12.160","status":"Analyzed","description":"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).","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/49f06cff50a4ccf3b7a1a662ceb892b3b21a527a","https://git.kernel.org/stable/c/9818bcae3c0ca1dde4b9a334125c46676e0a9b29","https://git.kernel.org/stable/c/aa4c4a9315764b2b7a7182e72cc5ea87520436b4","https://git.kernel.org/stable/c/d6998ddd507c81e3829489a6ead23f17f5acb7fe","https://git.kernel.org/stable/c/f41cf35ee2a1e31374b3f54e7579c55153506e70"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:46:40.600842820+00:00"},"epss":{"cve":"CVE-2026-64326","score":0.00159,"percentile":0.0506,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}