Commit ac5cc977 authored Dec 16, 2015 by WANG Cong Committed by David S. Miller Dec 17, 2015

net: check both type and procotol for tcp sockets



Dmitry reported the following out-of-bound access:

Call Trace:
 [<ffffffff816cec2e>] __asan_report_load4_noabort+0x3e/0x40
mm/kasan/report.c:294
 [<ffffffff84affb14>] sock_setsockopt+0x1284/0x13d0 net/core/sock.c:880
 [<     inline     >] SYSC_setsockopt net/socket.c:1746
 [<ffffffff84aed7ee>] SyS_setsockopt+0x1fe/0x240 net/socket.c:1729
 [<ffffffff85c18c76>] entry_SYSCALL_64_fastpath+0x16/0x7a
arch/x86/entry/entry_64.S:185

This is because we mistake a raw socket as a tcp socket.
We should check both sk->sk_type and sk->sk_protocol to ensure
it is a tcp socket.

Willem points out __skb_complete_tx_timestamp() needs to fix as well.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 67894eec

net/core/skbuff.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -3643,7 +3643,8 @@ static void __skb_complete_tx_timestamp(struct sk_buff *skb,
		serr->ee.ee_info = tstype;
		if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) {
		serr->ee.ee_data = skb_shinfo(skb)->tskey;
		if (sk->sk_protocol == IPPROTO_TCP)
		if (sk->sk_protocol == IPPROTO_TCP &&
		sk->sk_type == SOCK_STREAM)
		serr->ee.ee_data -= sk->sk_tskey;
		}

net/core/sock.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -872,7 +872,8 @@ int sock_setsockopt(struct socket *sock, int level, int optname,

		if (val & SOF_TIMESTAMPING_OPT_ID &&
		!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
		if (sk->sk_protocol == IPPROTO_TCP) {
		if (sk->sk_protocol == IPPROTO_TCP &&
		sk->sk_type == SOCK_STREAM) {
		if (sk->sk_state != TCP_ESTABLISHED) {
		ret = -EINVAL;
		break;