3.16.83-rc1 review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
commit 212e7f56605ef9688d0846db60c6c6ec06544095 upstream.
An earlier commit (1b789577f655060d98d20e, "netfilter: arp_tables: init netns pointer in xt_tgchk_param struct") fixed missing net initialization for arptables, but turns out it was incomplete. We can get a very similar struct net NULL deref during error unwinding:
general protection fault: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:xt_rateest_put+0xa1/0x440 net/netfilter/xt_RATEEST.c:77 xt_rateest_tg_destroy+0x72/0xa0 net/netfilter/xt_RATEEST.c:175 cleanup_entry net/ipv4/netfilter/arp_tables.c:509 [inline] translate_table+0x11f4/0x1d80 net/ipv4/netfilter/arp_tables.c:587 do_replace net/ipv4/netfilter/arp_tables.c:981 [inline] do_arpt_set_ctl+0x317/0x650 net/ipv4/netfilter/arp_tables.c:1461
Also init the netns pointer in xt_tgdtor_param struct.
Fixes: add67461240c1d ("netfilter: add struct net * to target parameters") Reported-by: syzbot+91bdd8eece0f6629ec8b@syzkaller.appspotmail.com Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org [bwh: Backported to 3.16: - __arpt_unregister_table() has not been split out of arpt_unregister_table() - Add "net" parameter to arpt_unregister_table() and update its only caller in arptable_filter.c] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/include/linux/netfilter_arp/arp_tables.h +++ b/include/linux/netfilter_arp/arp_tables.h @@ -51,7 +51,7 @@ extern void *arpt_alloc_initial_table(co extern struct xt_table *arpt_register_table(struct net *net, const struct xt_table *table, const struct arpt_replace *repl); -extern void arpt_unregister_table(struct xt_table *table); +extern void arpt_unregister_table(struct net *, struct xt_table *table); extern unsigned int arpt_do_table(struct sk_buff *skb, unsigned int hook, const struct net_device *in, --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -602,12 +602,13 @@ static inline int check_entry_size_and_h return 0; }
-static inline void cleanup_entry(struct arpt_entry *e) +static void cleanup_entry(struct arpt_entry *e, struct net *net) { struct xt_tgdtor_param par; struct xt_entry_target *t;
t = arpt_get_target(e); + par.net = net; par.target = t->u.kernel.target; par.targinfo = t->data; par.family = NFPROTO_ARP; @@ -706,7 +707,7 @@ static int translate_table(struct net *n xt_entry_foreach(iter, entry0, newinfo->size) { if (i-- == 0) break; - cleanup_entry(iter); + cleanup_entry(iter, net); } return ret; } @@ -1051,7 +1052,7 @@ static int __do_replace(struct net *net, /* Decrease module usage counts and free resource */ loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()]; xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net);
xt_free_table_info(oldinfo); if (copy_to_user(counters_ptr, counters, @@ -1118,7 +1119,7 @@ static int do_replace(struct net *net, c
free_newinfo_untrans: xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net); free_newinfo: xt_free_table_info(newinfo); return ret; @@ -1431,7 +1432,7 @@ static int compat_do_replace(struct net
free_newinfo_untrans: xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) - cleanup_entry(iter); + cleanup_entry(iter, net); free_newinfo: xt_free_table_info(newinfo); return ret; @@ -1708,7 +1709,7 @@ out: return ERR_PTR(ret); }
-void arpt_unregister_table(struct xt_table *table) +void arpt_unregister_table(struct net *net, struct xt_table *table) { struct xt_table_info *private; void *loc_cpu_entry; @@ -1720,7 +1721,7 @@ void arpt_unregister_table(struct xt_tab /* Decrease module usage counts and free resources */ loc_cpu_entry = private->entries[raw_smp_processor_id()]; xt_entry_foreach(iter, loc_cpu_entry, private->size) - cleanup_entry(iter); + cleanup_entry(iter, net); if (private->number > private->initial_entries) module_put(table_owner); xt_free_table_info(private); --- a/net/ipv4/netfilter/arptable_filter.c +++ b/net/ipv4/netfilter/arptable_filter.c @@ -54,7 +54,7 @@ static int __net_init arptable_filter_ne
static void __net_exit arptable_filter_net_exit(struct net *net) { - arpt_unregister_table(net->ipv4.arptable_filter); + arpt_unregister_table(net, net->ipv4.arptable_filter); }
static struct pernet_operations arptable_filter_net_ops = {