Description

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 btrfs_compress_filemap_get_folio() for S390 hardware acceleration path. [CAUSE] Before that commit, we call kumap_local() and folio_put() 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 folio_put() for copy_data_into_buffer().

Weaknesses 1

Affected Products 8

References 2

• git.kernel.org https://git.kernel.org/stable/c/0d0f1314e8f86f5205f71f9e31e272a1d008e40b
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e80617a5e1c246da2f112a1a072cdd535046adfe
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/0d0f1314e8f86f5205f71f9e31e272a1d008e40b
  Patch
• git.kernel.org https://git.kernel.org/stable/c/e80617a5e1c246da2f112a1a072cdd535046adfe
  Patch