4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit cba3f1786916063261e3e5ccbb803abc325b24ef ]
We changed tcp_poll() over time, bug never updated dccp.
Note that we also could remove dccp instead of maintaining it.
Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230818015820.2701595-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/dccp/proto.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 27de4dc1ff512..c4ea0159ce2e8 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -328,11 +328,15 @@ EXPORT_SYMBOL_GPL(dccp_disconnect);
__poll_t dccp_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
- __poll_t mask;
struct sock *sk = sock->sk;
+ __poll_t mask;
+ u8 shutdown;
+ int state;
sock_poll_wait(file, sock, wait);
- if (sk->sk_state == DCCP_LISTEN)
+
+ state = inet_sk_state_load(sk);
+ if (state == DCCP_LISTEN)
return inet_csk_listen_poll(sk);
/* Socket is not locked. We are protected from async events
@@ -341,20 +345,21 @@ __poll_t dccp_poll(struct file *file, struct socket *sock,
*/
mask = 0;
- if (sk->sk_err)
+ if (READ_ONCE(sk->sk_err))
mask = EPOLLERR;
+ shutdown = READ_ONCE(sk->sk_shutdown);
- if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
+ if (shutdown == SHUTDOWN_MASK || state == DCCP_CLOSED)
mask |= EPOLLHUP;
- if (sk->sk_shutdown & RCV_SHUTDOWN)
+ if (shutdown & RCV_SHUTDOWN)
mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
/* Connected? */
- if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
+ if ((1 << state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
if (atomic_read(&sk->sk_rmem_alloc) > 0)
mask |= EPOLLIN | EPOLLRDNORM;
- if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
+ if (!(shutdown & SEND_SHUTDOWN)) {
if (sk_stream_is_writeable(sk)) {
mask |= EPOLLOUT | EPOLLWRNORM;
} else { /* send SIGIO later */
@@ -372,7 +377,6 @@ __poll_t dccp_poll(struct file *file, struct socket *sock,
}
return mask;
}
-
EXPORT_SYMBOL_GPL(dccp_poll);
int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
--
2.40.1
