Btrfs-progs: fix array bound checking

Otherwise we can execced the array bound of path->slots[].

[Eric Sandeen: port kernel commit a05a9bb to userspace]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/ctree.c b/ctree.c
index 1a4f3f0..b07961b 100644 (file)
--- a/ctree.c
+++ b/ctree.c
@@ -827,9 +827,10 @@ static int balance_level(struct btrfs_trans_handle *trans,
 
        orig_ptr = btrfs_node_blockptr(mid, orig_slot);
 
-       if (level < BTRFS_MAX_LEVEL - 1)
+       if (level < BTRFS_MAX_LEVEL - 1) {
                parent = path->nodes[level + 1];
-       pslot = path->slots[level + 1];
+               pslot = path->slots[level + 1];
+       }
 
        /*
         * deal with the case where there is only one pointer in the root
@@ -1019,9 +1020,10 @@ static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
        mid = path->nodes[level];
        WARN_ON(btrfs_header_generation(mid) != trans->transid);
 
-       if (level < BTRFS_MAX_LEVEL - 1)
+       if (level < BTRFS_MAX_LEVEL - 1) {
                parent = path->nodes[level + 1];
-       pslot = path->slots[level + 1];
+               pslot = path->slots[level + 1];
+       }
 
        if (!parent)
                return 1;