From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Thu, 23 Nov 2006 11:03:24 +0000 (+0100)
Subject: [ALSA] sound: fix PCM substream list
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4d361285925613516560f81f8c7fc96b89c8b1a8;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[ALSA] sound: fix PCM substream list

If snd_pcm_new_stream() fails to initalize a substream (if
snd_pcm_substream_proc_init() returns error), snd_pcm_new_stream()
immediately return without unlinking that kfree()d substram.
It causes oops when snd_pcm_free() iterates the list of substream to
free them by invalid reference.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
---

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 5ac6e19ccb41..8e0189885516 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -640,6 +640,10 @@ int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
 		err = snd_pcm_substream_proc_init(substream);
 		if (err < 0) {
 			snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
+			if (prev == NULL)
+				pstr->substream = NULL;
+			else
+				prev->next = NULL;
 			kfree(substream);
 			return err;
 		}