From: Florian Westphal fw@strlen.de
[ Upstream commit 212e7f56605ef9688d0846db60c6c6ec06544095 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/netfilter/arp_tables.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index d819e91df90d6..e02b862651942 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -515,12 +515,13 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e, 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; @@ -612,7 +613,7 @@ static int translate_table(struct net *net, xt_entry_foreach(iter, entry0, newinfo->size) { if (i-- == 0) break; - cleanup_entry(iter); + cleanup_entry(iter, net); } return ret; } @@ -939,7 +940,7 @@ static int __do_replace(struct net *net, const char *name, /* Decrease module usage counts and free resource */ loc_cpu_old_entry = oldinfo->entries; 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, @@ -1003,7 +1004,7 @@ static int do_replace(struct net *net, const void __user *user,
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; @@ -1300,7 +1301,7 @@ static int compat_do_replace(struct net *net, void __user *user,
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; @@ -1527,7 +1528,7 @@ static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len return ret; }
-static void __arpt_unregister_table(struct xt_table *table) +static void __arpt_unregister_table(struct net *net, struct xt_table *table) { struct xt_table_info *private; void *loc_cpu_entry; @@ -1539,7 +1540,7 @@ static void __arpt_unregister_table(struct xt_table *table) /* Decrease module usage counts and free resources */ loc_cpu_entry = private->entries; 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); @@ -1579,7 +1580,7 @@ int arpt_register_table(struct net *net,
ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); if (ret != 0) { - __arpt_unregister_table(new_table); + __arpt_unregister_table(net, new_table); *res = NULL; }
@@ -1594,7 +1595,7 @@ void arpt_unregister_table(struct net *net, struct xt_table *table, const struct nf_hook_ops *ops) { nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); - __arpt_unregister_table(table); + __arpt_unregister_table(net, table); }
/* The built-in targets: standard (NULL) and error. */