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Message-ID: <913828319c9e0b6281ad32361e0246fc95d2c138.camel@gmail.com>
Subject: Re: [PATCH] media: sq905.c: fix uninitialized variable
From:   Pavel Skripkin <paskripkin@gmail.com>
To:     Dmitry Vyukov <dvyukov@google.com>,
        Greg KH <gregkh@linuxfoundation.org>
Cc:     Alaa Emad <alaaemadhossney.ae@gmail.com>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        syzkaller <syzkaller@googlegroups.com>,
        syzbot+a4e309017a5f3a24c7b3@syzkaller.appspotmail.com
Date:   Fri, 26 Mar 2021 10:24:29 +0300
In-Reply-To: <CACT4Y+Y8f6-c6zYCN=d0557xEryAzBfS9n2m=vBcdjHSi5gYcw@mail.gmail.com>
References: <20210325212202.142945-1-alaaemadhossney.ae@gmail.com>
         <YF2JF+UMdt/icEMj@kroah.com>
         <CACT4Y+Y8f6-c6zYCN=d0557xEryAzBfS9n2m=vBcdjHSi5gYcw@mail.gmail.com>
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Hi!

On Fri, 2021-03-26 at 08:14 +0100, 'Dmitry Vyukov' via syzkaller wrote:
> On Fri, Mar 26, 2021 at 8:11 AM Greg KH <gregkh@linuxfoundation.org>
> wrote:
> > 
> > On Thu, Mar 25, 2021 at 11:22:02PM +0200, Alaa Emad wrote:
> > > Reported-by: syzbot+a4e309017a5f3a24c7b3@syzkaller.appspotmail.com
> > > Signed-off-by: Alaa Emad <alaaemadhossney.ae@gmail.com>
> > > ---
> > 
> > I know I do not take patches with no changelog text, but other
> > maintainers might be more leniant :(
> 
> I wonder if it's the right fix or not.
> Initializing variables will, of course, silence the warning, but it's
> not necessarily the right fix. I suspect there is something wrong in
> how ret/act_len are user/checked.
> 

There is a problem in usb_bulk_msg() call. It could return before
act_len initialization, so i think, act_len should be intialized with
smth wrong like 0 or -1. BTW, I already send patch for that, but it was
marked as obsoleted.

--
With regards,

Pavel Skripkin