kernel: backport netfilter NAT offload support to 4.14

This only works with nftables for now, iptables support will be added
later. Includes a number of related upstream nftables improvements to
simplify backporting follow-up changes

Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 30 insertions, 0 deletions

diff --git a/target/linux/generic/backport-4.14/334-netfilter-nf_tables-fix-potential-NULL-ptr-deref-in-.patch b/target/linux/generic/backport-4.14/334-netfilter-nf_tables-fix-potential-NULL-ptr-deref-in-.patch
new file mode 100644
index 0000000000..57e9b53301
--- /dev/null
+++ b/target/linux/generic/backport-4.14/334-netfilter-nf_tables-fix-potential-NULL-ptr-deref-in-.patch
@@ -0,0 +1,30 @@
+From: Hangbin Liu <liuhangbin@gmail.com>
+Date: Mon, 25 Dec 2017 11:34:54 +0800
+Subject: [PATCH] netfilter: nf_tables: fix potential NULL-ptr deref in
+ nf_tables_dump_obj_done()
+
+If there is no NFTA_OBJ_TABLE and NFTA_OBJ_TYPE, the c.data will be NULL in
+nf_tables_getobj(). So before free filter->table in nf_tables_dump_obj_done(),
+we need to check if filter is NULL first.
+
+Fixes: e46abbcc05aa ("netfilter: nf_tables: Allow table names of up to 255 chars")
+Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
+Acked-by: Phil Sutter <phil@nwl.cc>
+Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
+---
+
+--- a/net/netfilter/nf_tables_api.c
++++ b/net/netfilter/nf_tables_api.c
+@@ -4614,8 +4614,10 @@ static int nf_tables_dump_obj_done(struc
+ {
+ 	struct nft_obj_filter *filter = cb->data;
+ 
+-	kfree(filter->table);
+-	kfree(filter);
++	if (filter) {
++		kfree(filter->table);
++		kfree(filter);
++	}
+ 
+ 	return 0;
+ }