[PATCH 5.15 076/132] netfilter: nft_flow_offload: skip dst neigh lookup for ppp devices

Greg Kroah-Hartman
2022-05-23T17:39:01Z

From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit 45ca3e61999e9a30ca2b7cfbf9da8a9f8d13be31 ]

The dst entry does not contain a valid hardware address, so skip the lookup
in order to avoid running into errors here.
The proper hardware address is filled in from nft_dev_path_info

Fixes: 72efd585f714 ("netfilter: flowtable: add pppoe support")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nft_flow_offload.c | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 0af34ad41479..dd824193c920 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -36,6 +36,15 @@ static void nft_default_forward_path(struct nf_flow_route *route,
route->tuple[dir].xmit_type = nft_xmit_type(dst_cache);
}

+static bool nft_is_valid_ether_device(const struct net_device *dev)
+{
+ if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
+ dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
+ return false;
+
+ return true;
+}
+
static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
const struct dst_entry *dst_cache,
const struct nf_conn *ct,
@@ -47,6 +56,9 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
struct neighbour *n;
u8 nud_state;

+ if (!nft_is_valid_ether_device(dev))
+ goto out;
+
n = dst_neigh_lookup(dst_cache, daddr);
if (!n)
return -1;
@@ -60,6 +72,7 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
if (!(nud_state & NUD_VALID))
return -1;

+out:
return dev_fill_forward_path(dev, ha, stack);
}

@@ -78,15 +91,6 @@ struct nft_forward_info {
enum flow_offload_xmit_type xmit_type;
};

-static bool nft_is_valid_ether_device(const struct net_device *dev)
-{
- if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
- dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
- return false;
-
- return true;
-}
-
static void nft_dev_path_info(const struct net_device_path_stack *stack,
struct nft_forward_info *info,
unsigned char *ha, struct nf_flowtable *flowtable)
--
2.35.1