nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 7.2.4
- 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: nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file ->atomic_open is permitted to return success without actually opening the file. It indicates this by calling finish_no_open(). This means dentry_create() can return a file which hasn't been opened. This is extremely unlikely as ->atomic_open handlers typically use finish_no_open() only for already existing files, and dentry_create() isn't called in that case, and the parent being locked should prevent races. However out of an abundance of caution it seems wise to teach nfsd to only use the file returned by dentry_create() if FMODE_OPENED is set, indicating that it has in fact been opened.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 64a989dbd144e0622371396461b11335459692d2 · fixed in a95a1cffacd0203100297001719160160f443dd6; From 64a989dbd144e0622371396461b11335459692d2 · fixed in 5859cc01fee06a2cd7458905a9593082fbab06e1
- Linux Linux
7.0
- KernelLinux
From 7.0.0 · fixed in 7.2.4