[PATCH 2/2] vsock: fix possible infinite sleep in vsock_connectible_wait_data()
From: Dexuan Cui <decui@microsoft.com>
Date: 2022-10-28 20:58:17
Also in:
linux-hyperv, lkml
Subsystem:
networking [general], the rest, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefano Garzarella
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 qeuue before checking
vsock_connectible_has_data().
Fixes: b3f7fd54881b ("af_vsock: separate wait data loop")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
net/vmw_vsock/af_vsock.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index d258fd43092e..03a6b5bc6ba7 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) ||
@@ -1937,6 +1940,8 @@ static int vsock_connectible_wait_data(struct sock *sk, err = -EAGAIN; break; } + + finish_wait(sk_sleep(sk), wait); } finish_wait(sk_sleep(sk), wait);
--
2.25.1