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> --- Changes in v2 (Thanks Stefano!): Fixed a typo in the commit message. Removed the unnecessary finish_wait() at the end of the loop. 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 d258fd43092e..884eca7f6743 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1905,8 +1905,11 @@ 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) || -- 2.25.1