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net: check both type and procotol for tcp sockets
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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>
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WANG Cong authored and David S. Miller committed Dec 17, 2015
1 parent 67894ee commit ac5cc97
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Showing 2 changed files with 4 additions and 2 deletions.
3 changes: 2 additions & 1 deletion net/core/skbuff.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}

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3 changes: 2 additions & 1 deletion net/core/sock.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
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