video: fbdev: aty: do not leak uninitialized padding in clk to userspace

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
index 11026e7..81367cf 100644 (file)
--- 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 *info, u_int cmd, u_long arg)
 #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;