Patch-mainline: v6.2-rc3
Git-commit: 7a4efe182ca61fb3e5307e69b261c57cbf434cd4
References: git-fixes
From: Yuan Can <yuancan@huawei.com>
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 <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: Juergen Gross <jgross@suse.com>
---
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)
ret = vsock_core_init(&vhost_transport.transport);
if (ret < 0)
return ret;
- return misc_register(&vhost_vsock_misc);
+
+ ret = misc_register(&vhost_vsock_misc);
+ if (ret) {
+ vsock_core_exit();
+ return ret;
+ }
+
+ return 0;
};
static void __exit vhost_vsock_exit(void)
--
2.35.3