xfs: add bounds checking to xfs_rt{bitmap,summary}_read_buf

Add a corruption check for passing an invalid block number, which is a
lot easier to understand than the xfs_bmapi_read failure later on.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

1 files changed, 30 insertions, 1 deletions

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 4de97c4e8ebd..02d6668d860f 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -69,7 +69,7 @@ xfs_rtbuf_cache_relse(
  * Get a buffer for the bitmap or summary file block specified.
  * The buffer is returned read and locked.
  */
-int
+static int
 xfs_rtbuf_get(
 	struct xfs_rtalloc_args	*args,
 	xfs_fileoff_t		block,	/* block number in bitmap or summary */
@@ -138,6 +138,35 @@ xfs_rtbuf_get(
 	return 0;
 }
 
+int
+xfs_rtbitmap_read_buf(
+	struct xfs_rtalloc_args		*args,
+	xfs_fileoff_t			block)
+{
+	struct xfs_mount		*mp = args->mp;
+
+	if (XFS_IS_CORRUPT(mp, block >= mp->m_sb.sb_rbmblocks)) {
+		xfs_rt_mark_sick(mp, XFS_SICK_RT_BITMAP);
+		return -EFSCORRUPTED;
+	}
+
+	return xfs_rtbuf_get(args, block, 0);
+}
+
+int
+xfs_rtsummary_read_buf(
+	struct xfs_rtalloc_args		*args,
+	xfs_fileoff_t			block)
+{
+	struct xfs_mount		*mp = args->mp;
+
+	if (XFS_IS_CORRUPT(mp, block >= XFS_B_TO_FSB(mp, mp->m_rsumsize))) {
+		xfs_rt_mark_sick(args->mp, XFS_SICK_RT_SUMMARY);
+		return -EFSCORRUPTED;
+	}
+	return xfs_rtbuf_get(args, block, 1);
+}
+
 /*
  * Searching backward from start find the first block whose allocated/free state
  * is different from start's.