• Takashi Iwai's avatar
    ALSA: pcm: Remove WARN_ON() at snd_pcm_hw_params() error · e1a3a981
    Takashi Iwai authored
    snd_pcm_hw_params() (more exactly snd_pcm_hw_params_choose()) contains
    a check of the return error from snd_pcm_hw_param_first() and _last()
    with snd_BUG_ON() -- i.e. it may trigger WARN_ON() depending on the
    kconfig.
    
    This was a valid check in the past, as these functions shouldn't
    return any error if the parameters have been already refined via
    snd_pcm_hw_refine() beforehand.  However, the recent rewrite
    introduced a kmalloc() in snd_pcm_hw_refine() for removing VLA, and
    this brought a possibility to trigger an error.  As a result, syzbot
    caught lots of superfluous kernel WARN_ON() and paniced via fault
    injection.
    
    As the WARN_ON() is no longer valid with the introduction of
    kmalloc(), let's drop snd_BUG_ON() check, in order to make the world
    peaceful place again.
    
    Reported-by: syzbot+803e0047ac3a3096bb4f@syzkaller.appspotmail.com
    Fixes: 5730f9f7 ("ALSA: pcm: Remove VLA usage")
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
    e1a3a981
pcm_native.c 103 KB