[34-longterm 160/260] ALSA: sound/pci/rme9652: prevent reading uninitialized stack memory

Paul Gortmaker
2011-01-02T07:47:23Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

commit e68d3b316ab7b02a074edc4f770e6a746390cb7d upstream.

The SNDRV_HDSP_IOCTL_GET_CONFIG_INFO and
SNDRV_HDSP_IOCTL_GET_CONFIG_INFO ioctls in hdspm.c and hdsp.c allow
unprivileged users to read uninitialized kernel stack memory, because
several fields of the hdsp{m}_config_info structs declared on the stack
are not altered or zeroed before being copied back to the user. This
patch takes care of it.

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
sound/pci/rme9652/hdsp.c | 1 +
sound/pci/rme9652/hdspm.c | 1 +
2 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c
index b92adef..d6fa7bf 100644
--- a/sound/pci/rme9652/hdsp.c
+++ b/sound/pci/rme9652/hdsp.c
@@ -4609,6 +4609,7 @@ static int snd_hdsp_hwdep_ioctl(struct snd_hwdep *hw, struct file *file, unsigne
if (err < 0)
return err;

+ memset(&info, 0, sizeof(info));
spin_lock_irqsave(&hdsp->lock, flags);
info.pref_sync_ref = (unsigned char)hdsp_pref_sync_ref(hdsp);
info.wordclock_sync_check = (unsigned char)hdsp_wc_sync_check(hdsp);
diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c
index 547b713..0c98ef9 100644
--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -4127,6 +4127,7 @@ static int snd_hdspm_hwdep_ioctl(struct snd_hwdep * hw, struct file *file,

case SNDRV_HDSPM_IOCTL_GET_CONFIG_INFO:

+ memset(&info, 0, sizeof(info));
spin_lock_irq(&hdspm->lock);
info.pref_sync_ref = hdspm_pref_sync_ref(hdspm);
info.wordclock_sync_check = hdspm_wc_sync_check(hdspm);
--
1.7.3.3