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authorDarrick J. Wong <darrick.wong@oracle.com>2016-08-26 15:58:40 +1000
committerDave Chinner <david@fromorbit.com>2016-08-26 15:58:40 +1000
commited150e1a5cf20c04cf0b2d2c34e498fc1d6519be (patch)
tree867b5a19de18ad47ece6325be6ce8c6f986aaafd /fs/xfs
parent32438cf9d54bd53b531f6d98814e84dd278360c1 (diff)
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xfs: don't perform lookups on zero-height btrees
If the caller passes in a cursor to a zero-height btree (which is impossible), we never set block to anything but NULL, which causes the later dereference of it to crash. Instead, just return -EFSCORRUPTED. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/libxfs/xfs_btree.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index b5c213a051cd..33f14067c320 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1814,6 +1814,10 @@ xfs_btree_lookup(
XFS_BTREE_STATS_INC(cur, lookup);
+ /* No such thing as a zero-level tree. */
+ if (cur->bc_nlevels == 0)
+ return -EFSCORRUPTED;
+
block = NULL;
keyno = 0;