From 7a4efe182ca61fb3e5307e69b261c57cbf434cd4 Mon Sep 17 00:00:00 2001 From: Yuan Can Date: Tue, 8 Nov 2022 10:17:05 +0000 Subject: [PATCH] vhost/vsock: Fix error handling in vhost_vsock_init() A problem about modprobe vhost_vsock failed is triggered with the following log given: modprobe: ERROR: could not insert 'vhost_vsock': Device or resource busy The reason is that vhost_vsock_init() returns misc_register() directly without checking its return value, if misc_register() failed, it returns without calling vsock_core_unregister() on vhost_transport, resulting the vhost_vsock can never be installed later. A simple call graph is shown as below: vhost_vsock_init() vsock_core_register() # register vhost_transport misc_register() device_create_with_groups() device_create_groups_vargs() dev = kzalloc(...) # OOM happened # return without unregister vhost_transport Fix by calling vsock_core_unregister() when misc_register() returns error. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Yuan Can Message-Id: <20221108101705.45981-1-yuancan@huawei.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefano Garzarella Acked-by: Jason Wang --- drivers/vhost/vsock.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index cd6f7776013a..a2b374372363 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -959,7 +959,14 @@ static int __init vhost_vsock_init(void) VSOCK_TRANSPORT_F_H2G); if (ret < 0) return ret; - return misc_register(&vhost_vsock_misc); + + ret = misc_register(&vhost_vsock_misc); + if (ret) { + vsock_core_unregister(&vhost_transport.transport); + return ret; + } + + return 0; }; static void __exit vhost_vsock_exit(void)