At the implementation of the optional proc fs in rawmidi, I forgot that rmidi->ops itself is optional and can be NULL. Add the proper NULL check for avoiding the Oops.

Fixes: fa030f666d24 ("ALSA: ump: Additional proc output") Reported-and-tested-by: Mark Hills mark@xwax.org Closes: https://lore.kernel.org/r/ef9118c3-a2eb-d0ff-1efa-cc5fb6416bde@xwax.org Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/rawmidi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index ba06484ac4aa..1431cb997808 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -1770,7 +1770,7 @@ static void snd_rawmidi_proc_info_read(struct snd_info_entry *entry, if (IS_ENABLED(CONFIG_SND_UMP)) snd_iprintf(buffer, "Type: %s\n", rawmidi_is_ump(rmidi) ? "UMP" : "Legacy"); - if (rmidi->ops->proc_read) + if (rmidi->ops && rmidi->ops->proc_read) rmidi->ops->proc_read(entry, buffer); mutex_lock(&rmidi->open_mutex); if (rmidi->info_flags & SNDRV_RAWMIDI_INFO_OUTPUT) {