From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Thu, 7 Jan 2021 20:59:17 +0000 (-0500)
Subject: xfs: refactor file range validation
X-Git-Tag: v5.11.0-rc0~24
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=7626c690ec70f33f577639ebd97b431af5bf1e65;p=thirdparty%2Fxfsprogs-dev.git

xfs: refactor file range validation

Source kernel commit: 33005fd0a537501111fc97ec330b721388c6b451

Refactor all the open-coded validation of file block ranges into a
single helper, and teach the bmap scrubber to check the ranges.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---

diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 96fadc8f5..458085e34 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -6220,7 +6220,7 @@ xfs_bmap_validate_extent(
 {
 	struct xfs_mount	*mp = ip->i_mount;
 
-	if (irec->br_startoff + irec->br_blockcount <= irec->br_startoff)
+	if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
 		return __this_address;
 
 	if (XFS_IS_REALTIME_INODE(ip) && whichfork == XFS_DATA_FORK) {
diff --git a/libxfs/xfs_types.c b/libxfs/xfs_types.c
index 9d25de6bd..af9f63434 100644
--- a/libxfs/xfs_types.c
+++ b/libxfs/xfs_types.c
@@ -258,3 +258,28 @@ xfs_verify_dablk(
 
 	return dabno <= max_dablk;
 }
+
+/* Check that a file block offset does not exceed the maximum. */
+bool
+xfs_verify_fileoff(
+	struct xfs_mount	*mp,
+	xfs_fileoff_t		off)
+{
+	return off <= XFS_MAX_FILEOFF;
+}
+
+/* Check that a range of file block offsets do not exceed the maximum. */
+bool
+xfs_verify_fileext(
+	struct xfs_mount	*mp,
+	xfs_fileoff_t		off,
+	xfs_fileoff_t		len)
+{
+	if (off + len <= off)
+		return false;
+
+	if (!xfs_verify_fileoff(mp, off))
+		return false;
+
+	return xfs_verify_fileoff(mp, off + len - 1);
+}
diff --git a/libxfs/xfs_types.h b/libxfs/xfs_types.h
index 18e83ce46..064bd6e8c 100644
--- a/libxfs/xfs_types.h
+++ b/libxfs/xfs_types.h
@@ -203,5 +203,8 @@ bool xfs_verify_icount(struct xfs_mount *mp, unsigned long long icount);
 bool xfs_verify_dablk(struct xfs_mount *mp, xfs_fileoff_t off);
 void xfs_icount_range(struct xfs_mount *mp, unsigned long long *min,
 		unsigned long long *max);
+bool xfs_verify_fileoff(struct xfs_mount *mp, xfs_fileoff_t off);
+bool xfs_verify_fileext(struct xfs_mount *mp, xfs_fileoff_t off,
+		xfs_fileoff_t len);
 
 #endif	/* __XFS_TYPES_H__ */