drivers/char/hpet.c: fix information leak to userland

Structure info is copied to userland with some padding fields unitialized.
It leads to leaking of stack memory.

[[email protected]: remove now-unneeded zeroing of info->hi_ireqfreq]
Signed-off-by: Vasiliy Kulikov <[email protected]>
Cc: Clemens Ladisch <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index fcb5f0d6ce700f1e3414ab53234e824baa673629..55b8667f739f64a82731ab926738601825cbb00c 100644 (file)
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -596,11 +596,10 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
                break;
        case HPET_INFO:
                {
+                       memset(info, 0, sizeof(*info));
                        if (devp->hd_ireqfreq)
                                info->hi_ireqfreq =
                                        hpet_time_div(hpetp, devp->hd_ireqfreq);
-                       else
-                               info->hi_ireqfreq = 0;
                        info->hi_flags =
                            readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
                        info->hi_hpet = hpetp->hp_which;