This is a note to let you know that I've just added the patch titled vhost/vsock: Fix error handling in vhost_vsock_init() to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vhost-vsock-fix-error-handling-in-vhost_vsock_init.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 278cbdd65b74d771d365061c773642b75f35a620 Author: Yuan Can <yuancan@xxxxxxxxxx> Date: Tue Nov 8 10:17:05 2022 +0000 vhost/vsock: Fix error handling in vhost_vsock_init() [ 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@xxxxxxxxxx> Message-Id: <20221108101705.45981-1-yuancan@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 5703775af129..10a7d23731fe 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)