nilfs2: add missing check for inode numbers on directory entries
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
In the Linux kernel, the following vulnerability has been resolved: nilfs2: add missing check for inode numbers on directory entries Syzbot reported that mounting and unmounting a specific pattern of corrupted nilfs2 filesystem images causes a use-after-free of metadata file inodes, which triggers a kernel bug in lru_add_fn(). As Jan Kara pointed out, this is because the link count of a metadata file gets corrupted to 0, and nilfs_evict_inode(), which is called from iput(), tries to delete that inode (ifile inode in this case). The inconsistency occurs because directories containing the inode numbers of these metadata files that should not be visible in the namespace are read without checking. Fix this issue by treating the inode numbers of these internal files as errors in the sanity check helper when reading directory folios/pages. Also thanks to Hillf Danton and Matthew Wilcox for their initial mm-layer analysis.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
2.6.30
References 8
git.kernel.org
- stable/c/c33c2b0d92aa1c2262d999b2598ad6fbd53bd479
- stable/c/07c176e7acc5579c133bb923ab21316d192d0a95
- stable/c/2f2fa9cf7c3537958a82fbe8c8595a5eb0861ad7
- stable/c/b11e8fb93ea5eefb2e4e719497ea177a58ff6131
- stable/c/1b7d549ed2c1fa202c751b69423a0d3a6bd5a180
- stable/c/3ab40870edb883b9633dc5cd55f5a2a11afa618d
- stable/c/265fff1a01cdc083aeaf0d934c929db5cc64aebf
- stable/c/bb76c6c274683c8570ad788f79d4b875bde0e458