Medium 5.5Published Jun 26, 2026

CVE-2026-53320nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()

Updated under an hour ago (Oct 26, 2026, 5:00 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty() nilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks by comparing it with the current block number bd_blocknr. If they differ, the block is considered dead and skipped. However, bd_oblocknr should never be 0 since block 0 typically stores the primary superblock and is never a valid GC target block. A corrupted ioctl request with bd_oblocknr set to 0 causes the comparison to incorrectly match when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing the dead block check and calling nilfs_bmap_mark() on a non-existent block. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering the WARN_ON(ret == -ENOENT). Fix this by rejecting ioctl requests with bd_oblocknr set to 0 at the beginning of each iteration. [ryusuke: slightly modified the commit message and comments for accuracy]

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Jun 26, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before e0a0c4903cbba351f0f5b5d104960d3a5b23202f; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before 9472d37799a0b9ff9b99639f35961ac2f0b3c9be; 7942b919f7321f95a777d396ff7894a7a83dc9b0 builds before 65e07964b4b2daf9a54e686cf0fa72d74a9648a8; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before b88f905d4449b70da6bda547be546e365e44352e; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before 4525658002be3ad310b16bf8db48c8adb6a55d32; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before e5ff0ba4b6983cdbcc826efc201e7179ece5d46f; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before 94094e70fe292c9566502772d4d4d6d6a99204b1; from 7942b919f7321f95a777d396ff7894a7a83dc9b0 before be3e5d10643d3be1cbac9d9939f220a99253f980	CNA record
linux linux_kernel linux:linux_kernel	from 2.6.30 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33; from 6.19 before 7.0.10	NVD

References

References

https://git.kernel.org/stable/c/e0a0c4903cbba351f0f5b5d104960d3a5b23202f	patch
https://git.kernel.org/stable/c/9472d37799a0b9ff9b99639f35961ac2f0b3c9be	patch
https://git.kernel.org/stable/c/65e07964b4b2daf9a54e686cf0fa72d74a9648a8	patch
https://git.kernel.org/stable/c/b88f905d4449b70da6bda547be546e365e44352e	patch
https://git.kernel.org/stable/c/4525658002be3ad310b16bf8db48c8adb6a55d32	patch
https://git.kernel.org/stable/c/e5ff0ba4b6983cdbcc826efc201e7179ece5d46f	patch
https://git.kernel.org/stable/c/94094e70fe292c9566502772d4d4d6d6a99204b1	patch
https://git.kernel.org/stable/c/be3e5d10643d3be1cbac9d9939f220a99253f980	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.