Re: [PATCH] ALSA: pcm: oss: Use snd_pcm_kernel_write() in snd_pcm_oss_sync()

[Takashi Iwai]

On Sun, 17 May 2026 15:36:08 +0200,
Jiakai Xu wrote:
> 
> Thank you for your review, Takashi.
> 
> > Thanks for the patch.  I believe the problem is rather in
> > do_transfer() setting up a bogus iter for silencing unnecessarily.
> > So it's a bug introduced in the commit cf393babb37a ("ALSA: pcm: Add
> > copy ops with iov_iter").
> 
> I agree with your analysis. The root cause is indeed in
> interleaved_copy() ― it should not pass a NULL data pointer to
> do_transfer(), which then unnecessarily constructs an iov_iter.
> 
> > Could you verify whether the change below works instead?
> > noninterleaved_copy() has already the handling of NULL data.
> 
> Unfortunately, this crash was discovered through fuzzing, and
> the fuzzer did not generate a reproducer. As a result, I am unable to
> test the fix directly. However, the fix looks correct to me.

OK, no problem.  Then I'm going to submit a proper patch later.
Thanks for your checking!


Takashi