btrfs: don't check PageError in __extent_writepage
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.1.189, 6.4.7
- 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: btrfs: don't check PageError in __extent_writepage __extent_writepage currenly sets PageError whenever any error happens, and the also checks for PageError to decide if to call error handling. This leads to very unclear responsibility for cleaning up on errors. In the VM and generic writeback helpers the basic idea is that once I/O is fired off all error handling responsibility is delegated to the end I/O handler. But if that end I/O handler sets the PageError bit, and the submitter checks it, the bit could in some cases leak into the submission context for fast enough I/O. Fix this by simply not checking PageError and just using the local ret variable to check for submission errors. This also fundamentally solves the long problem documented in a comment in __extent_writepage by never leaking the error bit into the submission context.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
From 61391d562229ed94899ed4b4973dc2f0c015292a · fixed in 3c26023365a955d2d69355f5167508a963e44333; From 61391d562229ed94899ed4b4973dc2f0c015292a · fixed in d40be032ecd8ee1ca033bee43c7755d21fb4d72a; From 61391d562229ed94899ed4b4973dc2f0c015292a · fixed in 3e92499e3b004baffb479d61e191b41b604ece9a
- Linux Linux
3.16
- KernelLinux
From 3.16.0 · fixed in 6.1.189; From 6.2.0 · fixed in 6.4.7