From: DaeMyung Kang Date: Sun, 10 May 2026 17:11:14 +0000 (+0900) Subject: ntfs: restore $MFT mirror contents check X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2beaa98b46c4cc90ed8a674f27a586d7f547bbe5;p=thirdparty%2Fkernel%2Flinux.git ntfs: restore $MFT mirror contents check check_mft_mirror() still computes the number of bytes to validate in each mirrored MFT record, but the actual comparison against $MFTMirr was dropped when the superblock code was updated. As a result, mount misses a stale or inconsistent $MFTMirr as long as both records pass the structural baad-record checks. Restore the comparison and log an error when the primary $MFT record differs from its mirror copy. Returning false lets the existing mount error handling mark the volume as having NTFS errors and, with on_errors=remount-ro, continue read-only. The default on_errors=continue mount policy still allows the mount to proceed. Fixes: 6251f0b0de7d ("ntfs: update super block operations") Signed-off-by: DaeMyung Kang Signed-off-by: Namjae Jeon --- diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c index d282cf6e712e..9e321cc2febe 100644 --- a/fs/ntfs/super.c +++ b/fs/ntfs/super.c @@ -993,6 +993,13 @@ mft_unmap_out: ntfs_is_baad_recordp((__le32 *)kmirr)) bytes = vol->mft_record_size; } + /* Compare the two records. */ + if (memcmp(kmft, kmirr, bytes)) { + ntfs_error(sb, + "$MFT and $MFTMirr record %i do not match. Run chkdsk.", + i); + goto mm_unmap_out; + } kmft += vol->mft_record_size; kmirr += vol->mft_record_size; } while (++i < vol->mftmirr_size);