1 files changed, 8 insertions, 3 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index cedc366505bd..790de32cd7d4 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2829,14 +2829,20 @@ void ip_rt_multicast_event(struct in_device *in_dev)
 }
 
 #ifdef CONFIG_SYSCTL
-static int flush_delay;
-
 static int ipv4_sysctl_rtcache_flush(ctl_table *ctl, int write,
                                         struct file *filp, void __user *buffer,
                                         size_t *lenp, loff_t *ppos)
 {
         if (write) {
+                int flush_delay;
+                static DEFINE_MUTEX(flush_mutex);
+
+                mutex_lock(&flush_mutex);
+                ctl->data = &flush_delay;
                 proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+                ctl->data = NULL;
+                mutex_unlock(&flush_mutex);
+
                 rt_cache_flush(&init_net, flush_delay);
                 return 0;
         }
@@ -2865,7 +2871,6 @@ ctl_table ipv4_route_table[] = {
         {
                 .ctl_name       = NET_IPV4_ROUTE_FLUSH,
                 .procname       = "flush",
-                .data           = &flush_delay,
                 .maxlen         = sizeof(int),
                 .mode           = 0200,
                 .proc_handler   = &ipv4_sysctl_rtcache_flush,