tcp: ulp: fix possible crash in tcp_diag_get_aux_size()

tcp_diag_get_aux_size() can be called with sockets in any state.

icsk_ulp_ops is only present for full sockets.

For SYN_RECV or TIME_WAIT ones we would access garbage.

Fixes: 61723b393292 ("tcp: ulp: add functions to dump ulp-specific information")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Luke Hsiao <lukehsiao@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Cc: Davide Caratti <dcaratti@redhat.com>
Acked-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index babc156deabb573f11bba344215d2c3712c4a3cd..81a8221d650a94be53d17354c60ddd0c655eaccf 100644 (file)
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -163,7 +163,7 @@ static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
        }
 #endif
 
-       if (net_admin) {
+       if (net_admin && sk_fullsock(sk)) {
                const struct tcp_ulp_ops *ulp_ops;
 
                ulp_ops = icsk->icsk_ulp_ops;