From 9e037cb7972fab5a9f55bca4ebe6e4dbf7e160bc Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 30 Jul 2018 16:45:35 -0700 Subject: xfs: check for unknown v5 feature bits in superblock write verifier Make sure we never try to write the superblock with unknown feature bits set. We checked those at mount time, so if they're set now then memory is corrupt. Signed-off-by: Darrick J. Wong Reviewed-by: Eric Sandeen --- fs/xfs/libxfs/xfs_sb.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'fs/xfs') diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index 05e7ed1b8022..ca1b3a7a9171 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -166,7 +166,40 @@ xfs_validate_sb_write( if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_5) return 0; - /* XXX: For write validation, we don't need to check feature masks?? */ + /* + * Version 5 superblock feature mask validation. Reject combinations + * the kernel cannot support since we checked for unsupported bits in + * the read verifier, which means that memory is corrupt. + */ + if (xfs_sb_has_compat_feature(sbp, XFS_SB_FEAT_COMPAT_UNKNOWN)) { + xfs_warn(mp, +"Corruption detected in superblock compatible features (0x%x)!", + (sbp->sb_features_compat & XFS_SB_FEAT_COMPAT_UNKNOWN)); + return -EFSCORRUPTED; + } + + if (xfs_sb_has_ro_compat_feature(sbp, XFS_SB_FEAT_RO_COMPAT_UNKNOWN)) { + xfs_alert(mp, +"Corruption detected in superblock read-only compatible features (0x%x)!", + (sbp->sb_features_ro_compat & + XFS_SB_FEAT_RO_COMPAT_UNKNOWN)); + return -EFSCORRUPTED; + } + if (xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_UNKNOWN)) { + xfs_warn(mp, +"Corruption detected in superblock incompatible features (0x%x)!", + (sbp->sb_features_incompat & + XFS_SB_FEAT_INCOMPAT_UNKNOWN)); + return -EFSCORRUPTED; + } + if (xfs_sb_has_incompat_log_feature(sbp, + XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) { + xfs_warn(mp, +"Corruption detected in superblock incompatible log features (0x%x)!", + (sbp->sb_features_log_incompat & + XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)); + return -EFSCORRUPTED; + } /* * We can't read verify the sb LSN because the read verifier is called -- cgit v1.2.1