Merge tag 'nf-26-03-19' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Florian Westphal says:

====================
netfilter: updates for net

The following patchset contains Netfilter fixes for *net*:

1) Fix UaF when netfilter bpf link goes away while nfnetlink dumps
   current hook list, we have to wait until rcu readers are gone.

2) Fix UaF when flowtable fails to register all devices, similar
   bug as 1). From Pablo Neira Ayuso.

3) nfnetlink_osf fails to properly validate option length fields.
   From Weiming Shi.

netfilter pull request nf-26-03-19

* tag 'nf-26-03-19' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  nfnetlink_osf: validate individual option lengths in fingerprints
  netfilter: nf_tables: release flowtable after rcu grace period on error
  netfilter: bpf: defer hook memory release until rcu readers are done
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: Paolo Abeni

net/netfilter/nf_bpf_link.c

@@ -170,7 +170,7 @@ static int bpf_nf_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
 
 static const struct bpf_link_ops bpf_nf_link_lops = {
 	.release = bpf_nf_link_release,
-	.dealloc = bpf_nf_link_dealloc,
+	.dealloc_deferred = bpf_nf_link_dealloc,
 	.detach = bpf_nf_link_detach,
 	.show_fdinfo = bpf_nf_link_show_info,
 	.fill_link_info = bpf_nf_link_fill_link_info,

net/netfilter/nf_tables_api.c

@@ -9203,6 +9203,7 @@ static int nf_tables_newflowtable(struct sk_buff *skb,
 	return 0;
 
 err_flowtable_hooks:
+	synchronize_rcu();
 	nft_trans_destroy(trans);
 err_flowtable_trans:
 	nft_hooks_destroy(&flowtable->hook_list);

net/netfilter/nfnetlink_osf.c

@@ -302,7 +302,9 @@ static int nfnl_osf_add_callback(struct sk_buff *skb,
 {
 	struct nf_osf_user_finger *f;
 	struct nf_osf_finger *kf = NULL, *sf;
+	unsigned int tot_opt_len = 0;
 	int err = 0;
+	int i;
 
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
@@ -318,6 +320,17 @@ static int nfnl_osf_add_callback(struct sk_buff *skb,
 	if (f->opt_num > ARRAY_SIZE(f->opt))
 		return -EINVAL;
 
+	for (i = 0; i < f->opt_num; i++) {
+		if (!f->opt[i].length || f->opt[i].length > MAX_IPOPTLEN)
+			return -EINVAL;
+		if (f->opt[i].kind == OSFOPT_MSS && f->opt[i].length < 4)
+			return -EINVAL;
+
+		tot_opt_len += f->opt[i].length;
+		if (tot_opt_len > MAX_IPOPTLEN)
+			return -EINVAL;
+	}
+
 	if (!memchr(f->genre, 0, MAXGENRELEN) ||
 	    !memchr(f->subtype, 0, MAXGENRELEN) ||
 	    !memchr(f->version, 0, MAXGENRELEN))