From 64df6d525fcff1630098db9238bfd2b3e092d5c1 Mon Sep 17 00:00:00 2001 From: linzhang Date: Wed, 17 May 2017 12:05:07 +0800 Subject: [PATCH] net: x25: fix one potential use-after-free issue The function x25_init is not properly unregister related resources on error handler.It is will result in kernel oops if x25_init init failed, so add properly unregister call on error handler. Also, i adjust the coding style and make x25_register_sysctl properly return failure. Signed-off-by: linzhang Signed-off-by: David S. Miller --- include/net/x25.h | 4 ++-- net/x25/af_x25.c | 24 ++++++++++++++++-------- net/x25/sysctl_net_x25.c | 5 ++++- 3 files changed, 22 insertions(+), 11 deletions(-) diff --git a/include/net/x25.h b/include/net/x25.h index c383aa4edbf0..6d30a01d281d 100644 --- a/include/net/x25.h +++ b/include/net/x25.h @@ -298,10 +298,10 @@ void x25_check_rbuf(struct sock *); /* sysctl_net_x25.c */ #ifdef CONFIG_SYSCTL -void x25_register_sysctl(void); +int x25_register_sysctl(void); void x25_unregister_sysctl(void); #else -static inline void x25_register_sysctl(void) {}; +static inline int x25_register_sysctl(void) { return 0; }; static inline void x25_unregister_sysctl(void) {}; #endif /* CONFIG_SYSCTL */ diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 8b911c29860e..5a1a98df3499 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -1791,32 +1791,40 @@ void x25_kill_by_neigh(struct x25_neigh *nb) static int __init x25_init(void) { - int rc = proto_register(&x25_proto, 0); + int rc; - if (rc != 0) + rc = proto_register(&x25_proto, 0); + if (rc) goto out; rc = sock_register(&x25_family_ops); - if (rc != 0) + if (rc) goto out_proto; dev_add_pack(&x25_packet_type); rc = register_netdevice_notifier(&x25_dev_notifier); - if (rc != 0) + if (rc) goto out_sock; - pr_info("Linux Version 0.2\n"); + rc = x25_register_sysctl(); + if (rc) + goto out_dev; - x25_register_sysctl(); rc = x25_proc_init(); - if (rc != 0) - goto out_dev; + if (rc) + goto out_sysctl; + + pr_info("Linux Version 0.2\n"); + out: return rc; +out_sysctl: + x25_unregister_sysctl(); out_dev: unregister_netdevice_notifier(&x25_dev_notifier); out_sock: + dev_remove_pack(&x25_packet_type); sock_unregister(AF_X25); out_proto: proto_unregister(&x25_proto); diff --git a/net/x25/sysctl_net_x25.c b/net/x25/sysctl_net_x25.c index a06dfe143c67..ba078c85f0a1 100644 --- a/net/x25/sysctl_net_x25.c +++ b/net/x25/sysctl_net_x25.c @@ -73,9 +73,12 @@ static struct ctl_table x25_table[] = { { }, }; -void __init x25_register_sysctl(void) +int __init x25_register_sysctl(void) { x25_table_header = register_net_sysctl(&init_net, "net/x25", x25_table); + if (!x25_table_header) + return -ENOMEM; + return 0; } void x25_unregister_sysctl(void) -- 2.34.1