From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Fri, 5 Oct 2018 02:36:09 +0000 (-0500)
Subject: xfs: check leaf attribute block freemap in verifier
X-Git-Tag: v4.19.0-rc0~48
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f43b1b3704c87df6dd16a7420bb85b40320efd73;p=users%2Fhch%2Fxfsprogs.git

xfs: check leaf attribute block freemap in verifier

Source kernel commit: 65cfcc3897d7715a878b9f59736e7527ca27514f

Check the leaf attribute freemap when we're verifying the block.

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

diff --git a/libxfs/xfs_attr_leaf.c b/libxfs/xfs_attr_leaf.c
index 30b6990b8..70a48e3a9 100644
--- a/libxfs/xfs_attr_leaf.c
+++ b/libxfs/xfs_attr_leaf.c
@@ -239,6 +239,8 @@ xfs_attr3_leaf_verify(
 	struct xfs_attr_leafblock	*leaf = bp->b_addr;
 	struct xfs_perag		*pag = bp->b_pag;
 	struct xfs_attr_leaf_entry	*entries;
+	uint16_t			end;
+	int				i;
 
 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
 
@@ -284,6 +286,26 @@ xfs_attr3_leaf_verify(
 	/* XXX: need to range check rest of attr header values */
 	/* XXX: hash order check? */
 
+	/*
+	 * Quickly check the freemap information.  Attribute data has to be
+	 * aligned to 4-byte boundaries, and likewise for the free space.
+	 */
+	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
+		if (ichdr.freemap[i].base > mp->m_attr_geo->blksize)
+			return __this_address;
+		if (ichdr.freemap[i].base & 0x3)
+			return __this_address;
+		if (ichdr.freemap[i].size > mp->m_attr_geo->blksize)
+			return __this_address;
+		if (ichdr.freemap[i].size & 0x3)
+			return __this_address;
+		end = ichdr.freemap[i].base + ichdr.freemap[i].size;
+		if (end < ichdr.freemap[i].base)
+			return __this_address;
+		if (end > mp->m_attr_geo->blksize)
+			return __this_address;
+	}
+
 	return NULL;
 }