From: Dan Rosenberg <drosenberg@vsecurity.com>
Date: Wed, 15 Sep 2010 23:08:24 +0000 (-0400)
Subject: drivers/video/via/ioctl.c: prevent reading uninitialized stack memory
X-Git-Tag: v2.6.35.6~16
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=63e70525feb93ddfdadd2eb81d0a71a055343d99;p=karo-tx-linux.git

drivers/video/via/ioctl.c: prevent reading uninitialized stack memory

commit b4aaa78f4c2f9cde2f335b14f4ca30b01f9651ca upstream.

The VIAFB_GET_INFO device ioctl allows unprivileged users to read 246
bytes of uninitialized stack memory, because the "reserved" member of
the viafb_ioctl_info struct declared on the stack is 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: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/video/via/ioctl.c b/drivers/video/via/ioctl.c
index da03c074e32a..4d553d0b8d7a 100644
--- a/drivers/video/via/ioctl.c
+++ b/drivers/video/via/ioctl.c
@@ -25,6 +25,8 @@ int viafb_ioctl_get_viafb_info(u_long arg)
 {
 	struct viafb_ioctl_info viainfo;
 
+	memset(&viainfo, 0, sizeof(struct viafb_ioctl_info));
+
 	viainfo.viafb_id = VIAID;
 	viainfo.vendor_id = PCI_VIA_VENDOR_ID;