Re: [PATCH v2] ALSA: seq: resize buffer for overflow

[Mark Salyzyn <salyzyn@android.com>]

On 10/07/2017 02:39 AM, Takashi Iwai wrote:
> I doubt it came from snd_midi_event_encode_byte().
> Judging from the call trace below, the event originated from the OSS
> sequencer write, i.e. it received an OSS event packet, and it was
> delivered again to another OSS sequencer port back via dummy client.
>
> If so, it should have received some EV_SYSEX packet, and it was
> processed via snd_seq_oss_synth_sysex(), and the encoded event was
> delivered.
>
> Now the question is how it triggers this Oops.  I couldn't find any
> obvious cause, but one thing I noticed is a possible race when writing
> to OSS sequencer concurrently.  Something wrong might happen.

Concurrent writing, thanks, I will switch gears and see if that 
represents the replication path!
> BTW, about your patch is buggy regarding the call kmalloc() with
> GFP_KERNEL inside spinlock.

<urrrrk> yup, withdraw this patch, and please erase it from my permanent 
record ;->

Thanks for the review, it was immensely helpful!

-- Mark