[PATCH 4.9 63/64] video: fbdev: aty: do not leak uninitialized padding in clk to userspace

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vladis Dronov <vdronov@xxxxxxxxxx>

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@xxxxxxx>
Signed-off-by: Vladis Dronov <vdronov@xxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 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
@@ -1861,7 +1861,7 @@ 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;