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.

[akpm@linux-foundation.org: remove now-unneeded zeroing of info->hi_ireqfreq]
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index fcb5f0d6ce70..55b8667f739f 100644
--- 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;