Re: [BUG] ALSA: ice1712: a possible sleep-in-atomic-context bug in snd_vt1724_set_pro_rate()

From: Takashi Iwai
Date: Wed Dec 18 2019 - 14:24:44 EST


On Wed, 18 Dec 2019 13:25:42 +0100,
Jia-Ju Bai wrote:
>
> The driver may sleep while holding a read lock.
> The function call path (from bottom to top) in Linux 4.19 is:
>
> sound/pci/ice1712/quartet.c, 414:
> ÂÂÂ mutex_lock in reg_write
> sound/pci/ice1712/quartet.c, 485:
> ÂÂÂ reg_write in set_cpld
> sound/pci/ice1712/quartet.c, 876:
> ÂÂÂ set_cpld in qtet_set_rate
> sound/pci/ice1712/ice1724.c, 687:
> ÂÂÂ (FUNC_PTR) qtet_set_rate in snd_vt1724_set_pro_rate
> sound/pci/ice1712/ice1724.c, 668:
> ÂÂÂ _raw_spin_lock_irqsave in snd_vt1724_set_pro_rate
>
> (FUNC_PTR) means a function pointer is called.
> mutex_lock() can sleep at runtime.
>
> I am not sure how to properly fix this possible bug, so I only report it.
>
> This bug is found by a static analysis tool STCheck written by myself.

Thanks for the report. I'll submitted the fix.


Takashi