Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: iomap: avoid potential null folio->mapping deref during error reporting When a buffered read fails, iomap_finish_folio_read() reports the error with fserror_report_io(folio->mapping->host, ...). This is called after ifs->read_bytes_pending has been decremented by the bytes attempted to be read. For a folio split across multiple read completions, the folio is only guaranteed to stay locked while read_bytes_pending > 0. Once iomap_finish_folio_read() decrements read_bytes_pending, another in-flight read can complete and end the read on the folio, which unlocks it. This allows truncate logic to run and detach the folio (set folio->mapping to NULL). The error reporting path then can dereference a NULL folio->mapping. As reported by Sam Sun, this is the race that can occur: CPU0: failed completion CPU1: final completion CPU2: truncate ----------------------- ---------------------- -------------- read_bytes_pending -= len finished = false /* preempted before fserror_report_io() */ read_bytes_pending -= len finished = true folio_end_read() truncate clears folio->mapping fserror_report_io( folio->mapping->host, ...) ^ NULL deref Fix this by reporting the error first before decrementing ifs->read_bytes_pending.
References
- https://git.kernel.org/stable/c/1ad453817a4077230d1ba88eb0868f05f824449a
- https://git.kernel.org/stable/c/2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327
FAQ
What is CVE-2026-53165?
CVE-2026-53165 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: iomap: avoid potential null folio->mapping deref during error reporting When a buffered read fails, iomap_finish_folio_read() repo...
How severe is CVE-2026-53165?
CVSS scoring is not yet available for CVE-2026-53165. Check NVD for updates.
Is there a patch for CVE-2026-53165?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.