[Dapper] [CVE-2010-4080] [CVE-2010-4081] [PATCH 1/1] ALSA: sound/pci/rme9652: prevent reading uninitialized stack memory, CVE-2010-4080, CVE-2010-4081

[Brad Figg]

From: Dan Rosenberg <drosenberg at vsecurity.com>

CVE-2010-4080
CVE-2010-4081

BugLink: http://bugs.launchpad.net/bugs/712723
BugLink: http://bugs.launchpad.net/bugs/712737

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

(backported from commit e68d3b316ab7b02a074edc4f770e6a746390cb7d)
Signed-off-by: Brad Figg <brad.figg at canonical.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 d15ffb3..a8c1ccc 100644
--- a/sound/pci/rme9652/hdsp.c
+++ b/sound/pci/rme9652/hdsp.c
@@ -4463,6 +4463,7 @@ static int snd_hdsp_hwdep_ioctl(snd_hwdep_t *hw, struct file *file, unsigned int
 			snd_printk(KERN_ERR "Hammerfall-DSP: Firmware needs to be uploaded to the card.\n");	
 			return -EINVAL;
 		}
+		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 4846e98..2e61b87 100644
--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -3217,6 +3217,7 @@ static int snd_hdspm_hwdep_ioctl(snd_hwdep_t * 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 =
 		    (unsigned char) hdspm_pref_sync_ref(hdspm);
-- 
1.7.3.5