ALSA: pcm: Free chmap at PCM free callback, too (a8ff48cb) · Commits · 戴 / test

The chmap ctls assigned to PCM streams are freed in the PCM disconnect callback. However, since the disconnect callback isn't called when the card gets freed before registering, the chmap ctls may still be left assigned. They are eventually freed together with other ctls, but it may cause an Oops at pcm_chmap_ctl_private_free(), as the function refers to the assigned PCM stream, while the PCM objects have been already freed beforehand. The fix is to free the chmap ctls also at PCM free callback, not only at PCM disconnect. Reported-by:

Laxminath Kasam <b_lkasam@codeaurora.org> Cc: <stable@vger.kernel.org> Signed-off-by:

Takashi Iwai <tiwai@suse.de>

sound/core/pcm.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -849,6 +849,14 @@ int snd_pcm_new_internal(struct snd_card card, const char id, int device,
		}
		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);
		pstr->chmap_kctl = NULL;
		}
		}

		static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
		{
		struct snd_pcm_substream substream, substream_next;
		@@ -871,6 +879,7 @@ static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
		kfree(setup);
		}
		#endif
		free_chmap(pstr);
		if (pstr->substream_count)
		put_device(&pstr->dev);
		}
		@@ -1135,10 +1144,7 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
		for (cidx = 0; cidx < 2; cidx++) {
		if (!pcm->internal)
		snd_unregister_device(&pcm->streams[cidx].dev);
		if (pcm->streams[cidx].chmap_kctl) {
		snd_ctl_remove(pcm->card, pcm->streams[cidx].chmap_kctl);
		pcm->streams[cidx].chmap_kctl = NULL;
		}
		free_chmap(&pcm->streams[cidx]);
		}
		mutex_unlock(&pcm->open_mutex);
		mutex_unlock(&register_mutex);

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