From: Jorgen Hansen Date: Fri, 24 Nov 2017 14:25:28 +0000 (-0800) Subject: VSOCK: Don't call vsock_stream_has_data in atomic context X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=afbea2cd253b5198350dfd8edb963567d05827d6;p=linux.git VSOCK: Don't call vsock_stream_has_data in atomic context When using the host personality, VMCI will grab a mutex for any queue pair access. In the detach callback for the vmci vsock transport, we call vsock_stream_has_data while holding a spinlock, and vsock_stream_has_data will access a queue pair. To avoid this, we can simply omit calling vsock_stream_has_data for host side queue pairs, since the QPs are empty per default when the guest has detached. This bug affects users of VMware Workstation using kernel version 4.4 and later. Testing: Ran vsock tests between guest and host, and verified that with this change, the host isn't calling vsock_stream_has_data during detach. Ran mixedTest between guest and host using both guest and host as server. v2: Rebased on top of recent change to sk_state values Reviewed-by: Adit Ranadive Reviewed-by: Aditya Sarwade Reviewed-by: Stefan Hajnoczi Signed-off-by: Jorgen Hansen Signed-off-by: David S. Miller --- diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c index 391775e3575c2..56573dc85709f 100644 --- a/net/vmw_vsock/vmci_transport.c +++ b/net/vmw_vsock/vmci_transport.c @@ -797,9 +797,13 @@ static void vmci_transport_handle_detach(struct sock *sk) /* We should not be sending anymore since the peer won't be * there to receive, but we can still receive if there is data - * left in our consume queue. + * left in our consume queue. If the local endpoint is a host, + * we can't call vsock_stream_has_data, since that may block, + * but a host endpoint can't read data once the VM has + * detached, so there is no available data in that case. */ - if (vsock_stream_has_data(vsk) <= 0) { + if (vsk->local_addr.svm_cid == VMADDR_CID_HOST || + vsock_stream_has_data(vsk) <= 0) { sk->sk_state = TCP_CLOSE; if (sk->sk_state == TCP_SYN_SENT) { @@ -2144,7 +2148,7 @@ module_exit(vmci_transport_exit); MODULE_AUTHOR("VMware, Inc."); MODULE_DESCRIPTION("VMCI transport for Virtual Sockets"); -MODULE_VERSION("1.0.4.0-k"); +MODULE_VERSION("1.0.5.0-k"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("vmware_vsock"); MODULE_ALIAS_NETPROTO(PF_VSOCK);