sysctl: fix proc_doulongvec_ms_jiffies_minmax()

commit ff9f8a7c upstream.

We perform the conversion between kernel jiffies and ms only when
exporting kernel value to user space.

We need to do the opposite operation when value is written by user.

Only matters when HZ != 1000
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

kernel/sysctl.c

@@ -2554,6 +2554,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 				break;
 			if (neg)
 				continue;
+			val = convmul * val / convdiv;
 			if ((min && val < *min) || (max && val > *max))
 				continue;
 			*i = val;