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Date:   Thu, 21 Apr 2022 15:30:41 +0200
From:   David Sterba <dsterba@suse.cz>
To:     Nikolay Borisov <nborisov@suse.com>
Cc:     Haowen Bai <baihaowen@meizu.com>, Chris Mason <clm@fb.com>,
        Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>, linux-btrfs@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] btrfs: Fix a memory leak in btrfs_ioctl_balance()
Message-ID: <20220421133041.GA18596@suse.cz>
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        Josef Bacik <josef@toxicpanda.com>, David Sterba <dsterba@suse.com>,
        linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
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On Thu, Apr 21, 2022 at 02:34:47PM +0300, Nikolay Borisov wrote:
> <snip>
> 
> > 
> > Actually to simplify further:
> > 
> > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> > index 7a6974e877f4..bbda55d41a06 100644
> > --- a/fs/btrfs/ioctl.c
> > +++ b/fs/btrfs/ioctl.c
> > @@ -4353,6 +4353,7 @@ static long btrfs_ioctl_balance(struct file *file, 
> > void __user *arg)
> >  ??????? bargs = memdup_user(arg, sizeof(*bargs));
> >  ??????? if (IS_ERR(bargs)) {
> >  ??????????????? ret = PTR_ERR(bargs);
> > +?????????????? bargs = NULL;
> >  ??????????????? goto out;
> >  ??????? }
> 
> Unf, this also leads to the double free ...

Please send me an incremental diff that I can fold to the patch, thanks.