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sound: Fix esoteric double free in the dummy sound driver. 

The dummy driver uses runtime->private_free but still frees
its pcm structures on error paths.

This is esoteric because the error paths in question are
unreachable. Thus the bug is only a problem when someone
copies this code into other drivers.

Signed-off-by: Daniel R Thompson <daniel.thompson@st.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Daniel THOMPSON 2008-08-15 10:53:38 +01:00 committed by Jaroslav Kysela
parent 8daaaa97d6
commit 54e8e21ed2
1 changed files with 4 additions and 6 deletions
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10
sound/drivers/dummy.c
View File

@ -354,6 +354,7 @@ static int snd_card_dummy_playback_open(struct snd_pcm_substream *substream)
if ((dpcm = new_pcm_stream(substream)) == NULL)
return -ENOMEM;
runtime->private_data = dpcm;
/* makes the infrastructure responsible for freeing dpcm */
runtime->private_free = snd_card_dummy_runtime_free;
runtime->hw = snd_card_dummy_playback;
if (substream->pcm->device & 1) {
@ -362,10 +363,8 @@ static int snd_card_dummy_playback_open(struct snd_pcm_substream *substream)
}
if (substream->pcm->device & 2)
runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
if ((err = add_playback_constraints(runtime)) < 0) {
kfree(dpcm);
if ((err = add_playback_constraints(runtime)) < 0)
return err;
}
return 0;
}
@ -379,6 +378,7 @@ static int snd_card_dummy_capture_open(struct snd_pcm_substream *substream)
if ((dpcm = new_pcm_stream(substream)) == NULL)
return -ENOMEM;
runtime->private_data = dpcm;
/* makes the infrastructure responsible for freeing dpcm */
runtime->private_free = snd_card_dummy_runtime_free;
runtime->hw = snd_card_dummy_capture;
if (substream->pcm->device == 1) {
@ -387,10 +387,8 @@ static int snd_card_dummy_capture_open(struct snd_pcm_substream *substream)
}
if (substream->pcm->device & 2)
runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP|SNDRV_PCM_INFO_MMAP_VALID);
if ((err = add_capture_constraints(runtime)) < 0) {
kfree(dpcm);
if ((err = add_capture_constraints(runtime)) < 0)
return err;
}
return 0;
}