From: Vasiliy Kulikov <segooon@gmail.com>
Date: Tue, 26 Oct 2010 21:22:15 +0000 (-0700)
Subject: drivers/char/hpet.c: fix information leak to userland
X-Git-Tag: firefly_0821_release~7613^2~3628^2~96
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dae512edc6e945e127f0848aa757055265d70aa2;p=firefly-linux-kernel-4.4.55.git

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>
---

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;