1 files changed, 18 insertions, 4 deletions

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index fbe7714f21d0..3cef12835c4b 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -33,6 +33,19 @@ EXPORT_SYMBOL(inet_csk_timer_bug_msg);
  * This array holds the first and last local port number.
  */
 int sysctl_local_port_range[2] = { 32768, 61000 };
+DEFINE_SEQLOCK(sysctl_port_range_lock);
+
+void inet_get_local_port_range(int *low, int *high)
+{
+        unsigned seq;
+        do {
+                seq = read_seqbegin(&sysctl_port_range_lock);
+
+                *low = sysctl_local_port_range[0];
+                *high = sysctl_local_port_range[1];
+        } while (read_seqretry(&sysctl_port_range_lock, seq));
+}
+EXPORT_SYMBOL(inet_get_local_port_range);
 
 int inet_csk_bind_conflict(const struct sock *sk,
                            const struct inet_bind_bucket *tb)
@@ -77,10 +90,11 @@ int inet_csk_get_port(struct inet_hashinfo *hashinfo,
 
         local_bh_disable();
         if (!snum) {
-                int low = sysctl_local_port_range[0];
-                int high = sysctl_local_port_range[1];
-                int remaining = (high - low) + 1;
-                int rover = net_random() % (high - low) + low;
+                int remaining, rover, low, high;
+
+                inet_get_local_port_range(&low, &high);
+                remaining = high - low;
+                rover = net_random() % remaining + low;
 
                 do {
                         head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];