Re: [PATCH] mwifiex: don't call del_timer_sync() on uninitialized timer

[Tetsuo Handa]

Ganapathi, how do you want to fix this bug?

On 2020/07/29 3:45, Brian Norris wrote:
>> syzbot is reporting that del_timer_sync() is called from
>> mwifiex_usb_cleanup_tx_aggr() from mwifiex_unregister_dev() without
>> checking timer_setup() from mwifiex_usb_tx_init() was called [1].
>> Since mwifiex_usb_prepare_tx_aggr_skb() is calling del_timer() if
>> is_hold_timer_set == true, use the same condition for del_timer_sync().
>>
>> [1] https://syzkaller.appspot.com/bug?id=fdeef9cf7348be8b8ab5b847f2ed993aba8ea7b6
>>
>> Reported-by: syzbot <syzbot+373e6719b49912399d21@xxxxxxxxxxxxxxxxxxxxxxxxx>
>> Cc: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
>> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
>> ---
>> A patch from Ganapathi Bhat ( https://patchwork.kernel.org/patch/10990275/ ) is stalling
>> at https://lore.kernel.org/linux-usb/MN2PR18MB2637D7C742BC235FE38367F0A09C0@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ .
>> syzbot by now got this report for 10000 times. Do we want to go with this simple patch?
> 
> Sorry, that stall is partly my fault, and partly Ganapathi's. It
> doesn't help that it took him 4 months to reply to my questions, so I
> completely lost even the tiny bit of context I had managed to build up
> in my head at initial review time... and so it's still buried in the
> dark corners of my inbox. (I think I'll go archive that now, because
> it really deserves a better sell than it had initially, if Ganapathi
> really wants to land it.)