lkml.org 
[lkml]   [2016]   [Aug]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/1] drm: avoid exposing kernel stack in compat_drm_getstats
Date
The C standard does not specify the size of the integer used
to store an enum. Hence in structure drm_stats32_t alignment
bytes may exist.

To avoid exposing bytes from the kernel stack it is
necessary to initialize variable s32 completely.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
drivers/gpu/drm/drm_ioc32.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
index 57676f8..32a489b 100644
--- a/drivers/gpu/drm/drm_ioc32.c
+++ b/drivers/gpu/drm/drm_ioc32.c
@@ -346,6 +346,7 @@ static int compat_drm_getstats(struct file *file, unsigned int cmd,
struct drm_stats __user *stats;
int i, err;

+ memset(&s32, 0, sizeof(drm_stats32_t));
stats = compat_alloc_user_space(sizeof(*stats));
if (!stats)
return -EFAULT;
--
2.1.4
\
 
 \ /
  Last update: 2016-09-17 09:57    [W:0.044 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site