From: Richard Weinberger <richard.weinberger@gmail.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Zhihao Cheng <chengzhihao1@huawei.com>,
Richard Weinberger <richard@nod.at>,
"zhangyi (F)" <yi.zhang@huawei.com>,
linux-mtd@lists.infradead.org,
LKML <linux-kernel@vger.kernel.org>,
Artem Bityutskiy <dedekind1@gmail.com>
Subject: Re: [PATCH] ubifs: do_kill_orphans: Fix a memory leak bug
Date: Tue, 29 Oct 2019 11:25:01 +0100 [thread overview]
Message-ID: <CAFLxGvw2UAXjz4uZ49gpxavBVjm7f8rT1agtmESsBkH70M-DaQ@mail.gmail.com> (raw)
In-Reply-To: <20191029092057.fsklsibqrmbmacar@pengutronix.de>
On Tue, Oct 29, 2019 at 10:21 AM Sascha Hauer <s.hauer@pengutronix.de> wrote:
>
> On Tue, Oct 29, 2019 at 05:01:10PM +0800, Zhihao Cheng wrote:
> > If there are more than one valid snod on the sleb->nodes list,
> > do_kill_orphans will malloc ino more than once without releasing
> > previous ino's memory. Finally, it will trigger memory leak.
> >
> > Fixes: ee1438ce5dc4 ("ubifs: Check link count of inodes when...")
> > Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
> > Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
> > ---
> > fs/ubifs/orphan.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/ubifs/orphan.c b/fs/ubifs/orphan.c
> > index 3b4b411..f211ed3 100644
> > --- a/fs/ubifs/orphan.c
> > +++ b/fs/ubifs/orphan.c
> > @@ -673,9 +673,11 @@ static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
> > if (first)
> > first = 0;
> >
> > - ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
> > - if (!ino)
> > - return -ENOMEM;
> > + if (!ino) {
> > + ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
> > + if (!ino)
> > + return -ENOMEM;
> > + }
>
> This solves only part of the problem. There are several places in the
> loop that just return instead of jumping to out_free. These need to be
> fixed as well.
> I am not sure if it's worth it to allocate ino on demand. It would be
> more straight forward to allocate it once initially before the loop.
> Not sure though what Richard prefers.
Yeah, allocating it outside the loop once would be the best solution.
I don't know why I did it in the loop. ;-\
--
Thanks,
//richard
prev parent reply other threads:[~2019-10-29 10:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 9:01 [PATCH] ubifs: do_kill_orphans: Fix a memory leak bug Zhihao Cheng
2019-10-29 9:20 ` Sascha Hauer
2019-10-29 10:25 ` Richard Weinberger [this message]
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