CVE-2026-23147: btrfs: zlib: fix the folio leak on S390 hardware acceleration
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zlib: fix the folio leak on S390 hardware acceleration
[BUG] After commit aa60fe12b4f4 ("btrfs: zlib: refactor S390x HW acceleration buffer preparation"), we no longer release the folio of the page cache of folio returned by btrfscompressfilemapgetfolio() for S390 hardware acceleration path.
[CAUSE] Before that commit, we call kumaplocal() and folioput() after handling each folio.
Although the timing is not ideal (it release previous folio at the beginning of the loop, and rely on some extra cleanup out of the loop), it at least handles the folio release correctly.
Meanwhile the refactored code is easier to read, it lacks the call to release the filemap folio.
[FIX] Add the missing folioput() for copydataintobuffer().
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-23147?
CVE-2026-23147 has a medium severity rating of 5.5 according to the CVSS v3.1 system.
What does CVE-2026-23147 affect?
CVE-2026-23147 affects the Linux kernel, specifically the btrfs filesystem and its zlib compression functionality.
How do I fix CVE-2026-23147?
The fix for CVE-2026-23147 is available as a patch that should be applied to the affected Linux kernel.
What is the impact of CVE-2026-23147?
The impact of CVE-2026-23147 includes the potential leak of folios in the page cache which can lead to denial of service.
When was CVE-2026-23147 published?
CVE-2026-23147 was published on February 14, 2026.