* [PATCH] gma/gma500: fix a memory disclosure bug due to uninitialized bytes
@ 2019-10-18 4:29 Kangjie Lu
2019-10-22 8:56 ` Daniel Vetter
0 siblings, 1 reply; 2+ messages in thread
From: Kangjie Lu @ 2019-10-18 4:29 UTC (permalink / raw)
To: kjlu
Cc: Patrik Jakobsson, David Airlie, Daniel Vetter, dri-devel, linux-kernel
`best_clock` is an object that may be sent out. Object `clock`
contains uninitialized bytes that are copied to `best_clock`,
which leads to memory disclosure and information leak.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
---
drivers/gpu/drm/gma500/cdv_intel_display.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/gma500/cdv_intel_display.c b/drivers/gpu/drm/gma500/cdv_intel_display.c
index f56852a503e8..8b784947ed3b 100644
--- a/drivers/gpu/drm/gma500/cdv_intel_display.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_display.c
@@ -405,6 +405,8 @@ static bool cdv_intel_find_dp_pll(const struct gma_limit_t *limit,
struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
struct gma_clock_t clock;
+ memset(&clock, 0, sizeof(clock));
+
switch (refclk) {
case 27000:
if (target < 200000) {
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] gma/gma500: fix a memory disclosure bug due to uninitialized bytes
2019-10-18 4:29 [PATCH] gma/gma500: fix a memory disclosure bug due to uninitialized bytes Kangjie Lu
@ 2019-10-22 8:56 ` Daniel Vetter
0 siblings, 0 replies; 2+ messages in thread
From: Daniel Vetter @ 2019-10-22 8:56 UTC (permalink / raw)
To: Kangjie Lu
Cc: Patrik Jakobsson, David Airlie, Daniel Vetter, dri-devel, linux-kernel
On Thu, Oct 17, 2019 at 11:29:53PM -0500, Kangjie Lu wrote:
> `best_clock` is an object that may be sent out. Object `clock`
> contains uninitialized bytes that are copied to `best_clock`,
> which leads to memory disclosure and information leak.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/gpu/drm/gma500/cdv_intel_display.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/gma500/cdv_intel_display.c b/drivers/gpu/drm/gma500/cdv_intel_display.c
> index f56852a503e8..8b784947ed3b 100644
> --- a/drivers/gpu/drm/gma500/cdv_intel_display.c
> +++ b/drivers/gpu/drm/gma500/cdv_intel_display.c
> @@ -405,6 +405,8 @@ static bool cdv_intel_find_dp_pll(const struct gma_limit_t *limit,
> struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
> struct gma_clock_t clock;
>
> + memset(&clock, 0, sizeof(clock));
I guess whatever analyzer you use for this doesn't see past the ->clock
vfunc call, so shouldn't be a real issue. Also, it's not an information
disclosure since we only ever leak this to other kernel code, never
userspace.
But I guess doesn't hurt, so applied.
-Daniel
> +
> switch (refclk) {
> case 27000:
> if (target < 200000) {
> --
> 2.17.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
^ permalink raw reply [flat|nested] 2+ messages in thread
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2019-10-22 8:56 ` Daniel Vetter
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