btrfs-progs: fix unaligned u64 access in btrfs_alloc_data_chunk

The key.offset member is not well-aligned as the key is packed, use a
temporary variable to pass the argument. Reported by ASAN in misc test
002.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/volumes.c b/volumes.c
index 70d894099cd8b0aa7ddefeb81ac4fe4995436ddd..c128472dbfe7f34fff55d966e8bdb8f9227f2fb4 100644 (file)
--- a/volumes.c
+++ b/volumes.c
@@ -1080,9 +1080,12 @@ int btrfs_alloc_data_chunk(struct btrfs_trans_handle *trans,
                key.offset = *start;
                dev_offset = *start;
        } else {
+               u64 tmp;
+
                ret = find_next_chunk(chunk_root,
                                      BTRFS_FIRST_CHUNK_TREE_OBJECTID,
-                                     &key.offset);
+                                     &tmp);
+               key.offset = tmp;
                if (ret)
                        return ret;
        }