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Message-ID: <c7af9f1a1c76ac56ec2a1e7470ae90a02a76365d.camel@gmail.com>
Subject: Re: [PATCH] media: usb: fix memory leak in em28xx_dvb_init
From:   Pavel Skripkin <paskripkin@gmail.com>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     "mchehab@kernel.org" <mchehab@kernel.org>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "syzbot+889397c820fa56adf25d@syzkaller.appspotmail.com" 
        <syzbot+889397c820fa56adf25d@syzkaller.appspotmail.com>
Date:   Sat, 27 Mar 2021 16:43:30 +0300
In-Reply-To: <CAHp75VcH9BpvRLcqY_LxyiycQ-pOpZP4QrJXYKe69zUDbYG=SA@mail.gmail.com>
References: <20210327082613.4702-1-paskripkin@gmail.com>
         <CAHp75VcH9BpvRLcqY_LxyiycQ-pOpZP4QrJXYKe69zUDbYG=SA@mail.gmail.com>
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Hi!

On Sat, 2021-03-27 at 11:01 +0200, Andy Shevchenko wrote:
> 
> 
> On Saturday, March 27, 2021, Pavel Skripkin <paskripkin@gmail.com>
> wrote:
> > syzbot reported memory leak in em28xx_dvb_init()[1]
> > The problem was in wrong error handling after
> > em28xx_alloc_urbs()[2]
> > call.
> > In case of error allocated urbs must be freed
> > 
> > 
> 
> I believe you may reduce twice the below backtrace and leave only
> important line(s).

Ok, I'll send new patch version soon.
Thank you!

> 
>  
> >   backtrace:
> >     [<ffffffff8304c141>] kmalloc_array.constprop.0+0x41/0x60
> > include/linux/slab.h:594
> >     [<ffffffff8304dba2>] kcalloc include/linux/slab.h:623 [inline]
> >     [<ffffffff8304dba2>] em28xx_alloc_urbs+0x102/0x550
> > drivers/media/usb/em28xx/em28xx-core.c:930 [2]
> >     [<ffffffff84279fa7>] em28xx_dvb_init
> > drivers/media/usb/em28xx/em28xx-dvb.c:1517 [inline]      [1]
> >     [<ffffffff84279fa7>] em28xx_dvb_init.cold+0xa3/0x2bb1
> > drivers/media/usb/em28xx/em28xx-dvb.c:1483
> >     [<ffffffff8304e33b>] em28xx_init_extension+0x9b/0xe0
> > drivers/media/usb/em28xx/em28xx-core.c:1126
> >     [<ffffffff83050143>] request_module_async+0x33/0x40
> > drivers/media/usb/em28xx/em28xx-cards.c:3406
> >     [<ffffffff81259229>] process_one_work+0x2c9/0x600
> > kernel/workqueue.c:2275
> >     [<ffffffff81259dbb>] process_scheduled_works
> > kernel/workqueue.c:2337 [inline]
> >     [<ffffffff81259dbb>] worker_thread+0x2fb/0x5d0
> > kernel/workqueue.c:2426
> >     [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292
> >     [<ffffffff8100227f>] ret_from_fork+0x1f/0x30
> > arch/x86/entry/entry_64.S:294
> > 
> > Reported-by: syzbot+889397c820fa56adf25d@syzkaller.appspotmail.com
> > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> > ---
> >  drivers/media/usb/em28xx/em28xx-dvb.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/media/usb/em28xx/em28xx-dvb.c
> > b/drivers/media/usb/em28xx/em28xx-dvb.c
> > index 526424279637..471bd74667e3 100644
> > --- a/drivers/media/usb/em28xx/em28xx-dvb.c
> > +++ b/drivers/media/usb/em28xx/em28xx-dvb.c
> > @@ -2010,6 +2010,7 @@ static int em28xx_dvb_init(struct em28xx
> > *dev)
> >         return result;
> > 
> >  out_free:
> > +       em28xx_uninit_usb_xfer(dev, EM28XX_DIGITAL_MODE);
> >         kfree(dvb);
> >         dev->dvb = NULL;
> >         goto ret;
> > -- 
> > 2.30.2
> > 
> > 
> 
> 

-- 
With regards,
Pavel Skripkin