[PATCH AUTOSEL 4.9 38/91] drm/gma500: fix memory disclosures due to uninitialized bytes

[Sasha Levin]

From: Kangjie Lu <kjlu@xxxxxxx>

[ Upstream commit ec3b7b6eb8c90b52f61adff11b6db7a8db34de19 ]

"clock" may be copied to "best_clock". Initializing best_clock
is not sufficient. The fix initializes clock as well to avoid
memory disclosures and informaiton leaks.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20191018044150.1899-1-kjlu@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/gma500/oaktrail_crtc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/gma500/oaktrail_crtc.c b/drivers/gpu/drm/gma500/oaktrail_crtc.c
index da9fd34b95505..caa6da02206aa 100644
--- a/drivers/gpu/drm/gma500/oaktrail_crtc.c
+++ b/drivers/gpu/drm/gma500/oaktrail_crtc.c
@@ -139,6 +139,7 @@ static bool mrst_sdvo_find_best_pll(const struct gma_limit_t *limit,
 	s32 freq_error, min_error = 100000;
 
 	memset(best_clock, 0, sizeof(*best_clock));
+	memset(&clock, 0, sizeof(clock));
 
 	for (clock.m = limit->m.min; clock.m <= limit->m.max; clock.m++) {
 		for (clock.n = limit->n.min; clock.n <= limit->n.max;
@@ -195,6 +196,7 @@ static bool mrst_lvds_find_best_pll(const struct gma_limit_t *limit,
 	int err = target;
 
 	memset(best_clock, 0, sizeof(*best_clock));
+	memset(&clock, 0, sizeof(clock));
 
 	for (clock.m = limit->m.min; clock.m <= limit->m.max; clock.m++) {
 		for (clock.p1 = limit->p1.min; clock.p1 <= limit->p1.max;
-- 
2.20.1