ALSA: PCM: Add missing rwsem around snd_ctl_remove() calls

[ Upstream commit 5471e9762e1af4b7df057a96bfd46cc250979b88 ]

snd_ctl_remove() has to be called with card->controls_rwsem held (when
called after the card instantiation).  This patch add the missing
rwsem calls around it.

Fixes: a8ff48cb7083 ("ALSA: pcm: Free chmap at PCM free callback, too")
Link: https://lore.kernel.org/r/20211116071314.15065-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 41cbdac..a8ae592 100644 (file)
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -810,7 +810,11 @@ EXPORT_SYMBOL(snd_pcm_new_internal);
 static void free_chmap(struct snd_pcm_str *pstr)
 {
        if (pstr->chmap_kctl) {
-               snd_ctl_remove(pstr->pcm->card, pstr->chmap_kctl);
+               struct snd_card *card = pstr->pcm->card;
+
+               down_write(&card->controls_rwsem);
+               snd_ctl_remove(card, pstr->chmap_kctl);
+               up_write(&card->controls_rwsem);
                pstr->chmap_kctl = NULL;
        }
 }