{"cve":"CVE-2026-53320","nvd":{"published":"2026-06-26T20:17:25.330","modified":"2026-07-06T20:12:14.333","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()\n\nnilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks\nby comparing it with the current block number bd_blocknr. If they differ,\nthe block is considered dead and skipped.\n\nHowever, bd_oblocknr should never be 0 since block 0 typically stores the\nprimary superblock and is never a valid GC target block. A corrupted ioctl\nrequest with bd_oblocknr set to 0 causes the comparison to incorrectly\nmatch when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing\nthe dead block check and calling nilfs_bmap_mark() on a non-existent\nblock. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering\nthe WARN_ON(ret == -ENOENT).\n\nFix this by rejecting ioctl requests with bd_oblocknr set to 0 at the\nbeginning of each iteration.\n\n[ryusuke: slightly modified the commit message and comments for accuracy]","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/4525658002be3ad310b16bf8db48c8adb6a55d32","https://git.kernel.org/stable/c/65e07964b4b2daf9a54e686cf0fa72d74a9648a8","https://git.kernel.org/stable/c/94094e70fe292c9566502772d4d4d6d6a99204b1","https://git.kernel.org/stable/c/9472d37799a0b9ff9b99639f35961ac2f0b3c9be","https://git.kernel.org/stable/c/b88f905d4449b70da6bda547be546e365e44352e"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53320","score":0.00173,"percentile":0.06686,"date":"2026-10-31"},"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."]}