fuse: reject oversized dirents in page cache
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- Fix
- Fixed in 6.18.25, 7.0.2
- 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
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse: reject oversized dirents in page cache fuse_add_dirent_to_cache() computes a serialized dirent size from the server-controlled namelen field and copies the dirent into a single page-cache page. The existing logic only checks whether the dirent fits in the remaining space of the current page and advances to a fresh page if not. It never checks whether the dirent itself exceeds PAGE_SIZE. As a result, a malicious FUSE server can return a dirent with namelen=4095, producing a serialized record size of 4120 bytes. On 4 KiB page systems this causes memcpy() to overflow the cache page by 24 bytes into the following kernel page. Reject dirents that cannot fit in a single page before copying them into the readdir cache.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 27992ef80770d61a57f6c3a551735b08cefdffa3 · fixed in 7de93abfaae1b2dc94da8a07a36421bd073f1d8f; From 27992ef80770d61a57f6c3a551735b08cefdffa3 · fixed in 474ce83c96a55f2eeb14dee2be375eeadfdacdf5; From 27992ef80770d61a57f6c3a551735b08cefdffa3 · fixed in 51a8de6c50bf947c8f534cd73da4c8f0a13e7bed
- Linux Linux
6.15
- KernelLinux
From 6.15.0 · fixed in 6.18.25; From 6.19.0 · fixed in 7.0.2