[PATCH 4.19 13/98] can: gw: Fix error path of cgw_module_init

[ 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)