Re: [PATCH v2 2/2] vsock: fix possible infinite sleep in vsock_connectible_wait_data()
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2022-11-02 09:32:56
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On Mon, Oct 31, 2022 at 07:17:06PM -0700, Dexuan Cui wrote:
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@microsoft.com>
---
Changes in v2 (Thanks Stefano!):
Fixed a typo in the commit message.
Removed the unnecessary finish_wait() at the end of the loop.LGTM: Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
quoted hunk ↗ jump to hunk
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