secondary address promotion causes infinite loop -- it arranges
for ifa->ifa_next to point back to itself.
Problem is that 'prev_prom' and 'last_prim' might point at the same entry,
so 'last_sec' pointer must be obtained after prev_prom->next update.
Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list")
Reported-by: Ran Rozenstein <ranro@mellanox.com>
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
if (prev_prom) {
struct in_ifaddr *last_sec;
- last_sec = rtnl_dereference(last_prim->ifa_next);
rcu_assign_pointer(prev_prom->ifa_next, next_sec);
+
+ last_sec = rtnl_dereference(last_prim->ifa_next);
rcu_assign_pointer(promote->ifa_next, last_sec);
rcu_assign_pointer(last_prim->ifa_next, promote);
}