btrfs: ref-verify: fix memory leak in add_block_entry

commit d60ba8de1164e1b42e296ff270c622a070ef8fe7 upstream.

clang static analysis flags this error

fs/btrfs/ref-verify.c:290:3: warning: Potential leak of memory pointed to by 're' [unix.Malloc]
                kfree(be);
                ^~~~~

The problem is in this block of code:

	if (root_objectid) {
		struct root_entry *exist_re;

		exist_re = insert_root_entry(&exist->roots, re);
		if (exist_re)
			kfree(re);
	}

There is no 'else' block freeing when root_objectid is 0. Add the
missing kfree to the else branch.

Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index 7887317033c98218a45bf710157fa37459d09b91..452ca955eb75edaa2dba177cb619d78cb736a190 100644 (file)
--- a/fs/btrfs/ref-verify.c
+++ b/fs/btrfs/ref-verify.c
@@ -286,6 +286,8 @@ static struct block_entry *add_block_entry(struct btrfs_fs_info *fs_info,
                        exist_re = insert_root_entry(&exist->roots, re);
                        if (exist_re)
                                kfree(re);
+               } else {
+                       kfree(re);
                }
                kfree(be);
                return exist;