btrfs: fix memory leak of path on error return path

Currently if the allocation of roots or tmp_ulist fails the error handling
does not free up the allocation of path causing a memory leak. Fix this and
other similar leaks by moving the call of btrfs_free_path from label out
to label out_free_ulist.

Kudos to David Sterba for spotting the issue in my original fix and suggesting
the correct way to fix the leak and Anand Jain for spotting a double free
issue.

Addresses-Coverity: ("Resource leak")
Fixes: 5911c8fe05c5 ("btrfs: fiemap: preallocate ulists for btrfs_check_shared")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 6b154bce5687..aea990473392 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4611,7 +4611,6 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         ret = btrfs_lookup_file_extent(NULL, root, path,
                         btrfs_ino(BTRFS_I(inode)), -1, 0);
         if (ret < 0) {
-                btrfs_free_path(path);
                 goto out_free_ulist;
         } else {
                 WARN_ON(!ret);
@@ -4764,11 +4763,11 @@ out_free:
                 ret = emit_last_fiemap_cache(fieinfo, &cache);
         free_extent_map(em);
 out:
-        btrfs_free_path(path);
         unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
                              &cached_state);
 
 out_free_ulist:
+        btrfs_free_path(path);
         ulist_free(roots);
         ulist_free(tmp_ulist);
         return ret;