Commit 4e08ed41 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix a data-race around sysctl_tcp_stdurg. 



While reading sysctl_tcp_stdurg, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1a63cb91

net/ipv4/tcp_input.c

+1 −1
Original line number Diff line number Diff line
@@ -5572,7 +5572,7 @@ static void tcp_check_urg(struct sock *sk, const struct tcphdr *th) 
	struct tcp_sock *tp = tcp_sk(sk);

	u32 ptr = ntohs(th->urg_ptr);



	if (ptr && !sock_net(sk)->ipv4.sysctl_tcp_stdurg)

	if (ptr && !READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_stdurg))

		ptr--;

	ptr += ntohl(th->seq);