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* [PATCH] sound: fix PCM substream list
@ 2006-11-22 18:51 Akinobu Mita
  2006-11-23 11:06 ` Takashi Iwai
  0 siblings, 1 reply; 2+ messages in thread
From: Akinobu Mita @ 2006-11-22 18:51 UTC (permalink / raw)
  To: linux-kernel; +Cc: Takashi Iwai, Jaroslav Kysela

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.

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

---
 sound/core/pcm.c |    4 ++++
 1 file changed, 4 insertions(+)

Index: work-fault-inject/sound/core/pcm.c
===================================================================
--- work-fault-inject.orig/sound/core/pcm.c
+++ work-fault-inject/sound/core/pcm.c
@@ -638,6 +638,10 @@ int snd_pcm_new_stream(struct snd_pcm *p
 		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;
 		}

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] sound: fix PCM substream list
  2006-11-22 18:51 [PATCH] sound: fix PCM substream list Akinobu Mita
@ 2006-11-23 11:06 ` Takashi Iwai
  0 siblings, 0 replies; 2+ messages in thread
From: Takashi Iwai @ 2006-11-23 11:06 UTC (permalink / raw)
  To: Akinobu Mita; +Cc: linux-kernel, Jaroslav Kysela

At Thu, 23 Nov 2006 03:51:45 +0900,
Akinobu Mita wrote:
> 
> 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.
> 
> Cc: Takashi Iwai <tiwai@suse.de>
> Cc: Jaroslav Kysela <perex@suse.cz>
> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

Merged this one to ALSA tree, too.
Thanks.


Takashi

> 
> ---
>  sound/core/pcm.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> Index: work-fault-inject/sound/core/pcm.c
> ===================================================================
> --- work-fault-inject.orig/sound/core/pcm.c
> +++ work-fault-inject/sound/core/pcm.c
> @@ -638,6 +638,10 @@ int snd_pcm_new_stream(struct snd_pcm *p
>  		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;
>  		}
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2006-11-23 11:06 UTC | newest]

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2006-11-22 18:51 [PATCH] sound: fix PCM substream list Akinobu Mita
2006-11-23 11:06 ` Takashi Iwai

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