Btrfs: add NULL check for do_walk_down()
btrfs_find_create_tree_block() may return NULL, so we must check the returned
value, or we will access a NULL pointer.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 1727b26..503a18e 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5205,6 +5205,8 @@
next = btrfs_find_tree_block(root, bytenr, blocksize);
if (!next) {
next = btrfs_find_create_tree_block(root, bytenr, blocksize);
+ if (!next)
+ return -ENOMEM;
reada = 1;
}
btrfs_tree_lock(next);
@@ -5417,7 +5419,8 @@
if (ret > 0) {
path->slots[level]++;
continue;
- }
+ } else if (ret < 0)
+ return ret;
level = wc->level;
}
return 0;