btrfs-progs: check path alloc in corrupt block

btrfs-corrupt-block added some untested path allocations.  These showed
up in static analysis when they pass their path to btrfs_search_slot()
which unconditionally dereferences the path.

Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
index c4f80fc..b40a529 100644 (file)
--- a/btrfs-corrupt-block.c
+++ b/btrfs-corrupt-block.c
@@ -601,6 +601,9 @@ int corrupt_chunk_tree(struct btrfs_trans_handle *trans,
        struct extent_buffer *leaf;
 
        path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
        key.objectid = (u64)-1;
        key.offset = (u64)-1;
        key.type = (u8)-1;
@@ -630,7 +633,7 @@ int corrupt_chunk_tree(struct btrfs_trans_handle *trans,
                if (ret)
                        goto free_out;
        }
-       btrfs_free_path(path);
+       btrfs_release_path(path);
 
        /* Here, cow and ins_len must equals 0 for the following reasons:
         * 1) chunk recover is based on disk scanning, so COW should be
@@ -639,7 +642,6 @@ int corrupt_chunk_tree(struct btrfs_trans_handle *trans,
         * 2) if cow = 0, ins_len must also be set to 0, or BUG_ON will be
         *    triggered.
         */
-       path = btrfs_alloc_path();
        ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
        BUG_ON(ret == 0);
        if (ret < 0) {
@@ -829,6 +831,10 @@ int main(int ac, char **av)
                        print_usage();
                del = rand() % 3;
                path = btrfs_alloc_path();
+               if (!path) {
+                       fprintf(stderr, "path allocation failed\n");
+                       goto out_close;
+               }
 
                if (find_chunk_offset(root->fs_info->chunk_root, path,
                                      logical) != 0) {