tipc: call start and done ops directly in __tipc_nl_compat_dumpit()
__tipc_nl_compat_dumpit() uses a netlink_callback on stack,
so the only way to align it with other ->dumpit() call path
is calling tipc_dump_start() and tipc_dump_done() directly
inside it. Otherwise ->dumpit() would always get NULL from
cb->args[].
But tipc_dump_start() uses sock_net(cb->skb->sk) to retrieve
net pointer, the cb->skb here doesn't set skb->sk, the net pointer
is saved in msg->net instead, so introduce a helper function
__tipc_dump_start() to pass in msg->net.
Ying pointed out cb->args[0...3] are already used by other
callbacks on this call path, so we can't use cb->args[0] any
more, use cb->args[4] instead.
Fixes: 9a07efa9aea2 ("tipc: switch to rhashtable iterator")
Reported-and-tested-by: syzbot+e93a2c41f91b8e2c7d9b@syzkaller.appspotmail.com
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a0ff8bf..3f03ddd 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3230,7 +3230,7 @@ int tipc_nl_sk_walk(struct sk_buff *skb, struct netlink_callback *cb,
struct netlink_callback *cb,
struct tipc_sock *tsk))
{
- struct rhashtable_iter *iter = (void *)cb->args[0];
+ struct rhashtable_iter *iter = (void *)cb->args[4];
struct tipc_sock *tsk;
int err;
@@ -3266,8 +3266,14 @@ EXPORT_SYMBOL(tipc_nl_sk_walk);
int tipc_dump_start(struct netlink_callback *cb)
{
- struct rhashtable_iter *iter = (void *)cb->args[0];
- struct net *net = sock_net(cb->skb->sk);
+ return __tipc_dump_start(cb, sock_net(cb->skb->sk));
+}
+EXPORT_SYMBOL(tipc_dump_start);
+
+int __tipc_dump_start(struct netlink_callback *cb, struct net *net)
+{
+ /* tipc_nl_name_table_dump() uses cb->args[0...3]. */
+ struct rhashtable_iter *iter = (void *)cb->args[4];
struct tipc_net *tn = tipc_net(net);
if (!iter) {
@@ -3275,17 +3281,16 @@ int tipc_dump_start(struct netlink_callback *cb)
if (!iter)
return -ENOMEM;
- cb->args[0] = (long)iter;
+ cb->args[4] = (long)iter;
}
rhashtable_walk_enter(&tn->sk_rht, iter);
return 0;
}
-EXPORT_SYMBOL(tipc_dump_start);
int tipc_dump_done(struct netlink_callback *cb)
{
- struct rhashtable_iter *hti = (void *)cb->args[0];
+ struct rhashtable_iter *hti = (void *)cb->args[4];
rhashtable_walk_exit(hti);
kfree(hti);