From: Cong Wang To: netdev@vger.kernel.org Cc: Cong Wang , Tony Ambardar , Jamal Hadi Salim , Jiri Pirko Subject: [Patch net] net_sched: fix a NULL pointer deref in ipt action Date: Sun, 25 Aug 2019 10:01:32 -0700 The net pointer in struct xt_tgdtor_param is not explicitly initialized therefore is still NULL when dereferencing it. So we have to find a way to pass the correct net pointer to ipt_destroy_target(). The best way I find is just saving the net pointer inside the per netns struct tcf_idrinfo, which could make this patch smaller. Fixes: 0c66dc1ea3f0 ("netfilter: conntrack: register hooks in netns when needed by ruleset") Reported-and-tested-by: Tony Ambardar Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang [Backported for kernel v4.14] Signed-off-by: Tony Ambardar --- include/net/act_api.h | 4 +++- net/sched/act_bpf.c | 2 +- net/sched/act_connmark.c | 2 +- net/sched/act_csum.c | 2 +- net/sched/act_gact.c | 2 +- net/sched/act_ife.c | 2 +- net/sched/act_ipt.c | 11 ++++++----- net/sched/act_mirred.c | 2 +- net/sched/act_nat.c | 2 +- net/sched/act_pedit.c | 2 +- net/sched/act_police.c | 2 +- net/sched/act_sample.c | 2 +- net/sched/act_simple.c | 2 +- net/sched/act_skbedit.c | 2 +- net/sched/act_skbmod.c | 2 +- net/sched/act_tunnel_key.c | 2 +- net/sched/act_vlan.c | 2 +- 17 files changed, 24 insertions(+), 21 deletions(-) --- a/include/net/act_api.h +++ b/include/net/act_api.h @@ -14,6 +14,7 @@ struct tcf_idrinfo { spinlock_t lock; struct idr action_idr; + struct net *net; }; struct tc_action_ops; @@ -104,7 +105,7 @@ struct tc_action_net { }; static inline -int tc_action_net_init(struct tc_action_net *tn, +int tc_action_net_init(struct net *net, struct tc_action_net *tn, const struct tc_action_ops *ops) { int err = 0; @@ -113,6 +114,7 @@ int tc_action_net_init(struct tc_action_ if (!tn->idrinfo) return -ENOMEM; tn->ops = ops; + tn->idrinfo->net = net; spin_lock_init(&tn->idrinfo->lock); idr_init(&tn->idrinfo->action_idr); return err; --- a/net/sched/act_bpf.c +++ b/net/sched/act_bpf.c @@ -402,7 +402,7 @@ static __net_init int bpf_init_net(struc { struct tc_action_net *tn = net_generic(net, bpf_net_id); - return tc_action_net_init(tn, &act_bpf_ops); + return tc_action_net_init(net, tn, &act_bpf_ops); } static void __net_exit bpf_exit_net(struct net *net) --- a/net/sched/act_connmark.c +++ b/net/sched/act_connmark.c @@ -206,7 +206,7 @@ static __net_init int connmark_init_net( { struct tc_action_net *tn = net_generic(net, connmark_net_id); - return tc_action_net_init(tn, &act_connmark_ops); + return tc_action_net_init(net, tn, &act_connmark_ops); } static void __net_exit connmark_exit_net(struct net *net) --- a/net/sched/act_csum.c +++ b/net/sched/act_csum.c @@ -632,7 +632,7 @@ static __net_init int csum_init_net(stru { struct tc_action_net *tn = net_generic(net, csum_net_id); - return tc_action_net_init(tn, &act_csum_ops); + return tc_action_net_init(net, tn, &act_csum_ops); } static void __net_exit csum_exit_net(struct net *net) --- a/net/sched/act_gact.c +++ b/net/sched/act_gact.c @@ -232,7 +232,7 @@ static __net_init int gact_init_net(stru { struct tc_action_net *tn = net_generic(net, gact_net_id); - return tc_action_net_init(tn, &act_gact_ops); + return tc_action_net_init(net, tn, &act_gact_ops); } static void __net_exit gact_exit_net(struct net *net) --- a/net/sched/act_ife.c +++ b/net/sched/act_ife.c @@ -837,7 +837,7 @@ static __net_init int ife_init_net(struc { struct tc_action_net *tn = net_generic(net, ife_net_id); - return tc_action_net_init(tn, &act_ife_ops); + return tc_action_net_init(net, tn, &act_ife_ops); } static void __net_exit ife_exit_net(struct net *net) --- a/net/sched/act_ipt.c +++ b/net/sched/act_ipt.c @@ -65,12 +65,13 @@ static int ipt_init_target(struct net *n return 0; } -static void ipt_destroy_target(struct xt_entry_target *t) +static void ipt_destroy_target(struct xt_entry_target *t, struct net *net) { struct xt_tgdtor_param par = { .target = t->u.kernel.target, .targinfo = t->data, .family = NFPROTO_IPV4, + .net = net, }; if (par.target->destroy != NULL) par.target->destroy(&par); @@ -82,7 +83,7 @@ static void tcf_ipt_release(struct tc_ac struct tcf_ipt *ipt = to_ipt(a); if (ipt->tcfi_t) { - ipt_destroy_target(ipt->tcfi_t); + ipt_destroy_target(ipt->tcfi_t, a->idrinfo->net); kfree(ipt->tcfi_t); } kfree(ipt->tcfi_tname); @@ -172,7 +173,7 @@ static int __tcf_ipt_init(struct net *ne spin_lock_bh(&ipt->tcf_lock); if (ret != ACT_P_CREATED) { - ipt_destroy_target(ipt->tcfi_t); + ipt_destroy_target(ipt->tcfi_t, net); kfree(ipt->tcfi_tname); kfree(ipt->tcfi_t); } @@ -337,7 +338,7 @@ static __net_init int ipt_init_net(struc { struct tc_action_net *tn = net_generic(net, ipt_net_id); - return tc_action_net_init(tn, &act_ipt_ops); + return tc_action_net_init(net, tn, &act_ipt_ops); } static void __net_exit ipt_exit_net(struct net *net) @@ -387,7 +388,7 @@ static __net_init int xt_init_net(struct { struct tc_action_net *tn = net_generic(net, xt_net_id); - return tc_action_net_init(tn, &act_xt_ops); + return tc_action_net_init(net, tn, &act_xt_ops); } static void __net_exit xt_exit_net(struct net *net) --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -343,7 +343,7 @@ static __net_init int mirred_init_net(st { struct tc_action_net *tn = net_generic(net, mirred_net_id); - return tc_action_net_init(tn, &act_mirred_ops); + return tc_action_net_init(net, tn, &act_mirred_ops); } static void __net_exit mirred_exit_net(struct net *net) --- a/net/sched/act_nat.c +++ b/net/sched/act_nat.c @@ -307,7 +307,7 @@ static __net_init int nat_init_net(struc { struct tc_action_net *tn = net_generic(net, nat_net_id); - return tc_action_net_init(tn, &act_nat_ops); + return tc_action_net_init(net, tn, &act_nat_ops); } static void __net_exit nat_exit_net(struct net *net) --- a/net/sched/act_pedit.c +++ b/net/sched/act_pedit.c @@ -458,7 +458,7 @@ static __net_init int pedit_init_net(str { struct tc_action_net *tn = net_generic(net, pedit_net_id); - return tc_action_net_init(tn, &act_pedit_ops); + return tc_action_net_init(net, tn, &act_pedit_ops); } static void __net_exit pedit_exit_net(struct net *net) --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -331,7 +331,7 @@ static __net_init int police_init_net(st { struct tc_action_net *tn = net_generic(net, police_net_id); - return tc_action_net_init(tn, &act_police_ops); + return tc_action_net_init(net, tn, &act_police_ops); } static void __net_exit police_exit_net(struct net *net) --- a/net/sched/act_sample.c +++ b/net/sched/act_sample.c @@ -249,7 +249,7 @@ static __net_init int sample_init_net(st { struct tc_action_net *tn = net_generic(net, sample_net_id); - return tc_action_net_init(tn, &act_sample_ops); + return tc_action_net_init(net, tn, &act_sample_ops); } static void __net_exit sample_exit_net(struct net *net) --- a/net/sched/act_simple.c +++ b/net/sched/act_simple.c @@ -198,7 +198,7 @@ static __net_init int simp_init_net(stru { struct tc_action_net *tn = net_generic(net, simp_net_id); - return tc_action_net_init(tn, &act_simp_ops); + return tc_action_net_init(net, tn, &act_simp_ops); } static void __net_exit simp_exit_net(struct net *net) --- a/net/sched/act_skbedit.c +++ b/net/sched/act_skbedit.c @@ -239,7 +239,7 @@ static __net_init int skbedit_init_net(s { struct tc_action_net *tn = net_generic(net, skbedit_net_id); - return tc_action_net_init(tn, &act_skbedit_ops); + return tc_action_net_init(net, tn, &act_skbedit_ops); } static void __net_exit skbedit_exit_net(struct net *net) --- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -267,7 +267,7 @@ static __net_init int skbmod_init_net(st { struct tc_action_net *tn = net_generic(net, skbmod_net_id); - return tc_action_net_init(tn, &act_skbmod_ops); + return tc_action_net_init(net, tn, &act_skbmod_ops); } static void __net_exit skbmod_exit_net(struct net *net) --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -324,7 +324,7 @@ static __net_init int tunnel_key_init_ne { struct tc_action_net *tn = net_generic(net, tunnel_key_net_id); - return tc_action_net_init(tn, &act_tunnel_key_ops); + return tc_action_net_init(net, tn, &act_tunnel_key_ops); } static void __net_exit tunnel_key_exit_net(struct net *net) --- a/net/sched/act_vlan.c +++ b/net/sched/act_vlan.c @@ -271,7 +271,7 @@ static __net_init int vlan_init_net(stru { struct tc_action_net *tn = net_generic(net, vlan_net_id); - return tc_action_net_init(tn, &act_vlan_ops); + return tc_action_net_init(net, tn, &act_vlan_ops); } static void __net_exit vlan_exit_net(struct net *net)