[PATCH AUTOSEL 4.19 15/68] can: gw: Fix error path of cgw_module_init

Sasha Levin
2019-08-14T02:32:31Z

From: YueHaibing <yuehaibing@huawei.com>

[ Upstream commit b7a14297f102b6e2ce6f16feffebbb9bde1e9b55 ]

This patch add error path for cgw_module_init to avoid possible crash if
some error occurs.

Fixes: c1aabdf379bc ("can-gw: add netlink based CAN routing")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/can/gw.c | 48 +++++++++++++++++++++++++++++++++---------------
1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/net/can/gw.c b/net/can/gw.c
index 53859346dc9a9..bd2161470e456 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -1046,32 +1046,50 @@ static __init int cgw_module_init(void)
pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n",
max_hops);

- register_pernet_subsys(&cangw_pernet_ops);
+ ret = register_pernet_subsys(&cangw_pernet_ops);
+ if (ret)
+ return ret;
+
+ ret = -ENOMEM;
cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
0, 0, NULL);
-
if (!cgw_cache)
- return -ENOMEM;
+ goto out_cache_create;

/* set notifier */
notifier.notifier_call = cgw_notifier;
- register_netdevice_notifier(&notifier);
+ ret = register_netdevice_notifier(&notifier);
+ if (ret)
+ goto out_register_notifier;

ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE,
NULL, cgw_dump_jobs, 0);
- if (ret) {
- unregister_netdevice_notifier(&notifier);
- kmem_cache_destroy(cgw_cache);
- return -ENOBUFS;
- }
-
- /* Only the first call to rtnl_register_module can fail */
- rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
- cgw_create_job, NULL, 0);
- rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
- cgw_remove_job, NULL, 0);
+ if (ret)
+ goto out_rtnl_register1;
+
+ ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE,
+ cgw_create_job, NULL, 0);
+ if (ret)
+ goto out_rtnl_register2;
+ ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE,
+ cgw_remove_job, NULL, 0);
+ if (ret)
+ goto out_rtnl_register3;

return 0;
+
+out_rtnl_register3:
+ rtnl_unregister(PF_CAN, RTM_NEWROUTE);
+out_rtnl_register2:
+ rtnl_unregister(PF_CAN, RTM_GETROUTE);
+out_rtnl_register1:
+ unregister_netdevice_notifier(&notifier);
+out_register_notifier:
+ kmem_cache_destroy(cgw_cache);
+out_cache_create:
+ unregister_pernet_subsys(&cangw_pernet_ops);
+
+ return ret;
}

static __exit void cgw_module_exit(void)
--
2.20.1