ceph: do not propagate page array emplacement errors as batch errors
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 6.13, 6.18.16, 6.19.6
- 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: ceph: do not propagate page array emplacement errors as batch errors When fscrypt is enabled, move_dirty_folio_in_page_array() may fail because it needs to allocate bounce buffers to store the encrypted versions of each folio. Each folio beyond the first allocates its bounce buffer with GFP_NOWAIT. Failures are common (and expected) under this allocation mode; they should flush (not abort) the batch. However, ceph_process_folio_batch() uses the same `rc` variable for its own return code and for capturing the return codes of its routine calls; failing to reset `rc` back to 0 results in the error being propagated out to the main writeback loop, which cannot actually tolerate any errors here: once `ceph_wbc.pages` is allocated, it must be passed to ceph_submit_write() to be freed. If it survives until the next iteration (e.g. due to the goto being followed), ceph_allocate_page_array()'s BUG_ON() will oops the worker. Note that this failure mode is currently masked due to another bug (addressed next in this series) that prevents multiple encrypted folios from being selected for the same write. For now, just reset `rc` when redirtying the folio to prevent errors in move_dirty_folio_in_page_array() from propagating. Note that move_dirty_folio_in_page_array() is careful never to return errors on the first folio, so there is no need to check for that. After this change, ceph_process_folio_batch() no longer returns errors; its only remaining failure indicator is `locked_pages == 0`, which the caller already handles correctly.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From ce80b76dd32764cc914975777e058d4fae4f0ea0 · fixed in 746840c87d76b614b14d9337c466ff022fc49823; From ce80b76dd32764cc914975777e058d4fae4f0ea0 · fixed in 4c0d84c788d89c167abf0bf84fd37890c4c84f08; From ce80b76dd32764cc914975777e058d4fae4f0ea0 · fixed in 707104682e3c163f7c14cdd6b07a3e95fb374759; From 6.12.114 · fixed in 6.13
- Linux Linux
6.15
- KernelLinux
From 6.15.0 · fixed in 6.18.16; From 6.19.0 · fixed in 6.19.6