2020-07-07 13:30:02

by Tom Rix

Subject: [PATCH] btrfs : fix memory leak in add_block_entry

From: Tom Rix <[email protected]>

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 <[email protected]>
---
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

2020-07-14 14:13:39

by David Sterba

Subject: Re: [PATCH] btrfs : fix memory leak in add_block_entry

On Tue, Jul 07, 2020 at 06:29:08AM -0700, [email protected] wrote:
> From: Tom Rix <[email protected]>
>
> 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 <[email protected]>

Added to misc-next, thanks.