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From:   trix@redhat.com
To:     clm@fb.com, josef@toxicpanda.com, dsterba@suse.com
Cc:     linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        Tom Rix <trix@redhat.com>
Subject: [PATCH] btrfs : fix memory leak in add_block_entry
Date:   Tue,  7 Jul 2020 06:29:08 -0700
Message-Id: <20200707132908.10987-1-trix@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Tom Rix <trix@redhat.com>

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 == 0

So add an 'else'

Fixes: fd708b81d972 ("Btrfs: add a extent ref verify tool")

Signed-off-by: Tom Rix <trix@redhat.com>
---
 fs/btrfs/ref-verify.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/ref-verify.c b/fs/btrfs/ref-verify.c
index af92525dbb16..7f03dbe5b609 100644
--- 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;
-- 
2.18.1