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 ac09d98490aabc0729eb1a4691e8d2b1ec10a34c..07f6fc468e1732734e7fcf5f73982a93670e4194 100644 (file)
--- 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;