Re: UBSAN: Undefined behaviour in drivers/net/wireless/intel/iwlwifi/mvm/utils.c:838:5

[Luca Coelho]

On Wed, 2017-12-13 at 16:32 +0200, Luciano Coelho wrote:
> On Wed, 2017-12-13 at 14:25 +0100, Paul Menzel wrote:
> > Dear Linux folks,
> > 
> > 
> > I enabled the undefined behavior sanitizer, and built Linusâ
> > master 
> > branch under Ubuntu 17.10 with gcc (Ubuntu 7.2.0-8ubuntu3) 7.2.0.
> > 
> > ```
> > $ grep UBSAN /boot/config-4.15.0-rc3+
> > CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
> > # CONFIG_ARCH_WANTS_UBSAN_NO_NULL is not set
> > CONFIG_UBSAN=y
> > CONFIG_UBSAN_SANITIZE_ALL=y
> > # CONFIG_UBSAN_ALIGNMENT is not set
> > CONFIG_UBSAN_NULL=y
> > ```
> > 
> > Starting the system the messages below are printed.
> > 
> > Starting the system and using the wireless device shows the
> > messages
> > below.
> 
> Thanks for reporting! This shouldn't cause any problems, but I'll fix
> it by checking that the mac80211_queue is not INVALID_QUEUE (255)
> which seems to be the trigger for this warning.

Can you try the following patch to see if the problem goes away?

http://pastebin.coelho.fi/7b624f474846da52.txt

Thanks!

--
Cheers,
Luca.