From: Yuan Can yuancan@huawei.com
[ Upstream commit 7a4efe182ca61fb3e5307e69b261c57cbf434cd4 ]
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 yuancan@huawei.com Message-Id: 20221108101705.45981-1-yuancan@huawei.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Acked-by: Jason Wang jasowang@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b0153617fe0e..7bce5f982e58 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -854,7 +854,14 @@ 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)