Description
In the Linux kernel, the following vulnerability has been resolved: erofs: fix managed cache race for unaligned extents After unaligned compressed extents were introduced, the following race could occur: [Thread 1] [Thread 2] (z_erofs_fill_bio_vec) <handle a Z_EROFS_PREALLOCATED_FOLIO folio> ... filemap_add_folio (1) (z_erofs_bind_cache) <the same folio is found..> .. .. folio_attach_private (2) filemap_add_folio (3) again Since (1) is executed but (2) hasn't been executed yet, it's possible that another thread finds the same managed folio in z_erofs_bind_cache() for a different pcluster and calls filemap_add_folio() again since folio->private is still Z_EROFS_PREALLOCATED_FOLIO. Fix this by explicitly clearing folio->private before making the folio visible in the managed cache so that another pcluster can simply wait on the locked managed folio as what we did for other shared cases [1]. This only impacts unaligned data compression (`-E48bit` with zstd, for example). [1] Commit 9e2f9d34dd12 ("erofs: handle overlapped pclusters out of crafted images properly") was originally introduced to handle crafted overlapped extents, but it addresses unaligned extents as well.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
722f0fcdb0bb7d12a5c6d9460b9a7de1f735f36d to < 2718cdb6db0fdbe375e61f2980aada27bafb323eaffected7361d1e3763baaf7b9349c576137851458ad38d1 to < 425d32d6288d7d845e486af9419bbedccd8c9103affected7361d1e3763baaf7b9349c576137851458ad38d1 to < 038166f873c4caf6e85cfd4ea0c5a5ba297b4e8baffected7361d1e3763baaf7b9349c576137851458ad38d1 to < 649932fc3815eda2f24eb4de4b3a5e94886ee0b9affected
Linux Linux
Default version status: affected
6.15affected0 to < 6.15unaffected6.18.34 to ≤ 6.18.*unaffected7.0.11 to ≤ 7.0.*unaffected7.1 to ≤ *unaffected