[34-longterm 144/260] drivers/video/via/ioctl.c: prevent reading uninitialized stack memory

Paul Gortmaker
2011-01-02T07:48:53Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

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: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/video/via/ioctl.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/video/via/ioctl.c b/drivers/video/via/ioctl.c
index da03c07..4d553d0 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;

--
1.7.3.3