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Date:   Fri, 29 Jul 2022 10:13:26 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Dipanjan Das <mail.dipanjan.das@gmail.com>
Cc:     Takashi Iwai <tiwai@suse.de>, perex@perex.cz, tiwai@suse.com,
        consult.awy@gmail.com, alsa-devel@alsa-project.org,
        linux-kernel@vger.kernel.org, syzkaller@googlegroups.com,
        fleischermarius@googlemail.com, its.priyanka.bose@gmail.com
Subject: Re: KASAN: vmalloc-out-of-bounds Write in snd_pcm_hw_params
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On Thu, Jul 28, 2022 at 04:24:12PM -0700, Dipanjan Das wrote:
> On Tue, Jul 26, 2022 at 10:25 PM Takashi Iwai <tiwai@suse.de> wrote:
> >
> > Thanks for the analysis.  A good news is that, at least for the
> > vmalloc() case, it's a kind of false-positive; vmalloc() always takes
> > the full pages, so practically seen, the size is page-aligned.  It's
> > fooling the memory checker, though.
> >
> > But the similar problem could be seen with genalloc calls, and this
> > was fixed by the upstream commit
> > 5c1733e33c888a3cb7f576564d8ad543d5ad4a9e
> >     ALSA: memalloc: Align buffer allocations in page size
> >
> > I suppose you can simply backport this commit to 5.10.y.  Could you
> > confirm that this fixes your problem?
> 
> We confirm that the patch you proposed fixes the problem (blocks the
> reproducer). How do we proceed with getting the issue fixed? Do we
> send a patch according to the steps detailed here:
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html?

Normally, yes, that is the correct process.  But as Takashi mentioned, I
already picked it up as I happened to see this thread.

thanks,

greg k-h