diff mbox

[02/55] xfs: check for bogus values in btree block headers

Message ID 148072892722.12995.6297042295929105024.stgit@birch.djwong.org (mailing list archive)
State Accepted
Headers show

Commit Message

Darrick J. Wong Dec. 3, 2016, 1:35 a.m. UTC
When we're reading a btree block, make sure that what we retrieved
matches the owner and level; and has a plausible number of records.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_btree.c |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)



--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 0e80993..21e6a6a 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1769,8 +1769,28 @@  xfs_btree_lookup_get_block(
 	if (error)
 		return error;
 
+	/* Check the inode owner since the verifiers don't. */
+	if (xfs_sb_version_hascrc(&cur->bc_mp->m_sb) &&
+	    (cur->bc_flags & XFS_BTREE_LONG_PTRS) &&
+	    be64_to_cpu((*blkp)->bb_u.l.bb_owner) !=
+			cur->bc_private.b.ip->i_ino)
+		goto out_bad;
+
+	/* Did we get the level we were looking for? */
+	if (be16_to_cpu((*blkp)->bb_level) != level)
+		goto out_bad;
+
+	/* Check that internal nodes have at least one record. */
+	if (level != 0 && be16_to_cpu((*blkp)->bb_numrecs) == 0)
+		goto out_bad;
+
 	xfs_btree_setbuf(cur, level, bp);
 	return 0;
+
+out_bad:
+	*blkp = NULL;
+	xfs_trans_brelse(cur->bc_tp, bp);
+	return -EFSCORRUPTED;
 }
 
 /*