[PATCH 3.16 135/192] video: fbdev: aty: do not leak uninitialized padding in clk to userspace

Ben Hutchings
2017-10-09T13:05:13Z

From: Vladis Dronov <vdronov@redhat.com>

commit 8e75f7a7a00461ef6d91797a60b606367f6e344d upstream.

'clk' is copied to a userland with padding byte(s) after 'vclk_post_div'
field unitialized, leaking data from the stack. Fix this ensuring all of
'clk' is initialized to zero.

References: https://github.com/torvalds/linux/pull/441
Reported-by: sohu0106 <sohu0106@126.com>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/video/fbdev/aty/atyfb_base.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/video/fbdev/aty/atyfb_base.c
+++ b/drivers/video/fbdev/aty/atyfb_base.c
@@ -1852,7 +1852,7 @@ static int atyfb_ioctl(struct fb_info *i
#if defined(DEBUG) && defined(CONFIG_FB_ATY_CT)
case ATYIO_CLKR:
if (M64_HAS(INTEGRATED)) {
- struct atyclk clk;
+ struct atyclk clk = { 0 };
union aty_pll *pll = &par->pll;
u32 dsp_config = pll->ct.dsp_config;
u32 dsp_on_off = pll->ct.dsp_on_off;