TT#14008 use interrupt-safe lock for ssrc_stats_lock

Despite this code being called from userspace, we must disable
interrupts while having ssrc_stats_lock acquired, as the same lock is
acquired elsewhere from within an interrupt context.

closes #1492

Change-Id: Ia6f31eb876ee98ad355d12f9361cbc068d008608
(cherry picked from commit e2ea393ecc)
(cherry picked from commit ce3703c329)
(cherry picked from commit 76c0fa96f8)

kernel-module/xt_RTPENGINE.c

@@ -1706,13 +1706,14 @@ static struct re_dest_addr *find_dest_addr(const struct re_dest_addr_hash *h, co
 
 static int table_get_target_stats(struct rtpengine_table *t, struct rtpengine_stats_info *i, int reset) {
 	struct rtpengine_target *g;
+	unsigned long flags;
 
 	g = get_target(t, &i->local);
 	if (!g)
 		return -ENOENT;
 
 	i->ssrc = g->target.ssrc;
-	spin_lock(&g->ssrc_stats_lock);
+	spin_lock_irqsave(&g->ssrc_stats_lock, flags);
 	i->ssrc_stats = g->ssrc_stats;
 
 	if (reset) {
@@ -1721,7 +1722,7 @@ static int table_get_target_stats(struct rtpengine_table *t, struct rtpengine_st
 		g->ssrc_stats.total_lost = 0;
 	}
 
-	spin_unlock(&g->ssrc_stats_lock);
+	spin_unlock_irqrestore(&g->ssrc_stats_lock, flags);
 
 	target_put(g);