From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
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 <darrick.wong@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_sb.c | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
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
--
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