[PATCH v1 net 1/4] neighbour: Add missing RCU annotation for neightbl_dump_info().

[Kuniyuki Iwashima <kuniyu@google.com>]

neightbl_dump_info() fetches the first non-default neigh_parms
with list_next_entry(&tbl->parms, ...) and iterates through the
list with list_for_each_entry_from_rcu().

However, list_next_entry() does not use RCU helper.

Let's fetch the default parms with list_first_entry() and
use list_for_each_entry_continue_rcu() for iteration.

Note that the first entry is always tbl->parms, which never goes
away, so list_first_entry(&tbl->parms_list, ...) is safe.

Fixes: 4ae34be50064 ("neighbour: Convert RTM_GETNEIGHTBL to RCU.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 net/core/neighbour.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 1349c0eedb64..4b17c2a15594 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2611,8 +2611,9 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb)
 			break;
 
 		nidx = 0;
-		p = list_next_entry(&tbl->parms, list);
-		list_for_each_entry_from_rcu(p, &tbl->parms_list, list) {
+
+		p = list_first_entry(&tbl->parms_list, struct neigh_parms, list);
+		list_for_each_entry_continue_rcu(p, &tbl->parms_list, list) {
 			if (!net_eq(neigh_parms_net(p), net))
 				continue;
 
-- 
2.55.0.1003.g10538fe699-goog