From: Francesco Fusco <ffusco@redhat.com>
Date: Wed, 24 Jul 2013 08:39:07 +0000 (+0200)
Subject: sysctl: range checking in do_proc_dointvec_ms_jiffies_conv
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=d738ce8fdc05ebf5b1475f8ae26d908c8c50970b;p=deliverable%2Flinux.git

sysctl: range checking in do_proc_dointvec_ms_jiffies_conv

When (integer) sysctl values are expressed in ms and have to be
represented internally as jiffies. The msecs_to_jiffies function
returns an unsigned long, which gets assigned to the integer.
This patch prevents the value to be assigned if bigger than
INT_MAX, done in a similar way as in cba9f3 ("Range checking in
do_proc_dointvec_(userhz_)jiffies_conv").

Signed-off-by: Francesco Fusco <ffusco@redhat.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index ac09d98490aa..07f6fc468e17 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2346,7 +2346,11 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
 					    int write, void *data)
 {
 	if (write) {
-		*valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
+
+		if (jif > INT_MAX)
+			return 1;
+		*valp = (int)jif;
 	} else {
 		int val = *valp;
 		unsigned long lval;