ALSA: sound/pci/rme9652: prevent reading uninitialized stack memory

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>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 2 insertions, 0 deletions

diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c
index b92adef8e81e..d6fa7bfd9aa1 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 547b713d7204..0c98ef9156d8 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);