From: Dexuan Cui <decui@xxxxxxxxxxxxx>
[ Upstream commit 466a85336fee6e3b35eb97b8405a28302fd25809 ]
Currently vsock_connectible_has_data() may miss a wakeup operation
between vsock_connectible_has_data() == 0 and the prepare_to_wait().
Fix the race by adding the process to the wait queue before checking
vsock_connectible_has_data().
Fixes: b3f7fd54881b ("af_vsock: separate wait data loop")
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Reported-by: Frédéric Dalleau <frederic.dalleau@xxxxxxxxxx>
Tested-by: Frédéric Dalleau <frederic.dalleau@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/vmw_vsock/af_vsock.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 5d46036f3ad7..dc36a46ce0e7 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1897,8 +1897,11 @@ static int vsock_connectible_wait_data(struct sock *sk,
err = 0;
transport = vsk->transport;
- while ((data = vsock_connectible_has_data(vsk)) == 0) {
+ while (1) {
prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
+ data = vsock_connectible_has_data(vsk);
+ if (data != 0)
+ break;
if (sk->sk_err != 0 ||
(sk->sk_shutdown & RCV_SHUTDOWN) ||
--
2.35.1
