fs: relax assertions on failure to encode file handles
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.1.151, 6.6.74, 6.12.10
- 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: fs: relax assertions on failure to encode file handles Encoding file handles is usually performed by a filesystem >encode_fh() method that may fail for various reasons. The legacy users of exportfs_encode_fh(), namely, nfsd and name_to_handle_at(2) syscall are ready to cope with the possibility of failure to encode a file handle. There are a few other users of exportfs_encode_{fh,fid}() that currently have a WARN_ON() assertion when ->encode_fh() fails. Relax those assertions because they are wrong. The second linked bug report states commit 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles") in v6.6 as the regressing commit, but this is not accurate. The aforementioned commit only increases the chances of the assertion and allows triggering the assertion with the reproducer using overlayfs, inotify and drop_caches. Triggering this assertion was always possible with other filesystems and other reasons of ->encode_fh() failures and more particularly, it was also possible with the exact same reproducer using overlayfs that is mounted with options index=on,nfs_export=on also on kernels < v6.6. Therefore, I am not listing the aforementioned commit as a Fixes commit. Backport hint: this patch will have a trivial conflict applying to v6.6.y, and other trivial conflicts applying to stable kernels < v6.6.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From be77196b809cdce8603a5aadd5e3cfabd3cbef96 · fixed in 73697928c806fe4689939722184a86fc1c1957b4; From be77196b809cdce8603a5aadd5e3cfabd3cbef96 · fixed in f47c834a9131ae64bee3c462f4e610c67b0a000f; From be77196b809cdce8603a5aadd5e3cfabd3cbef96 · fixed in adcde2872f8fc399b249758ae1990dcd53b694ea; From be77196b809cdce8603a5aadd5e3cfabd3cbef96 · fixed in 974e3fe0ac61de85015bbe5a4990cf4127b304b2
- Linux Linux
3.8
- KernelLinux
From 3.8.0 · fixed in 6.1.151; From 6.2.0 · fixed in 6.6.74; From 6.7.0 · fixed in 6.12.10