From: Davide Caratti Date: Wed, 26 Apr 2017 17:07:35 +0000 (+0200) Subject: tcp: fix access to sk->sk_state in tcp_poll() X-Git-Tag: v4.12-rc1~129^2~55 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=d68be71ea14d609a5f31534003319be5db422595;p=linux.git tcp: fix access to sk->sk_state in tcp_poll() avoid direct access to sk->sk_state when tcp_poll() is called on a socket using active TCP fastopen with deferred connect. Use local variable 'state', which stores the result of sk_state_load(), like it was done in commit 00fd38d938db ("tcp: ensure proper barriers in lockless contexts"). Fixes: 19f6d3f3c842 ("net/tcp-fastopen: Add new API support") Signed-off-by: Davide Caratti Acked-by: Wei Wang Signed-off-by: David S. Miller --- diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 059dad7deefe..1e4c76d2b827 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -533,7 +533,7 @@ unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) if (tp->urg_data & TCP_URG_VALID) mask |= POLLPRI; - } else if (sk->sk_state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { + } else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) { /* Active TCP fastopen socket with defer_connect * Return POLLOUT so application can call write() * in order for kernel to generate SYN+data