netdev - [PATCH net 2/3] netfilter: fib: check correct rtable in vrf setups

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20241009213858.3565808-3-pablo@netfilter.org>
Date: Wed,  9 Oct 2024 23:38:57 +0200
From: Pablo Neira Ayuso <pablo@...filter.org>
To: netfilter-devel@...r.kernel.org
Cc: davem@...emloft.net,
	netdev@...r.kernel.org,
	kuba@...nel.org,
	pabeni@...hat.com,
	edumazet@...gle.com,
	fw@...len.de
Subject: [PATCH net 2/3] netfilter: fib: check correct rtable in vrf setups

From: Florian Westphal <fw@...len.de>

We need to init l3mdev unconditionally, else main routing table is searched
and incorrect result is returned unless strict (iif keyword) matching is
requested.

Next patch adds a selftest for this.

Fixes: 2a8a7c0eaa87 ("netfilter: nft_fib: Fix for rpath check with VRF devices")
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1761
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/ipv4/netfilter/nft_fib_ipv4.c | 4 +---
 net/ipv6/netfilter/nft_fib_ipv6.c | 5 +++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/netfilter/nft_fib_ipv4.c b/net/ipv4/netfilter/nft_fib_ipv4.c
index 00da1332bbf1..09fff5d424ef 100644
--- a/net/ipv4/netfilter/nft_fib_ipv4.c
+++ b/net/ipv4/netfilter/nft_fib_ipv4.c
@@ -65,6 +65,7 @@ void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs,
 		.flowi4_scope = RT_SCOPE_UNIVERSE,
 		.flowi4_iif = LOOPBACK_IFINDEX,
 		.flowi4_uid = sock_net_uid(nft_net(pkt), NULL),
+		.flowi4_l3mdev = l3mdev_master_ifindex_rcu(nft_in(pkt)),
 	};
 	const struct net_device *oif;
 	const struct net_device *found;
@@ -83,9 +84,6 @@ void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs,
 	else
 		oif = NULL;
 
-	if (priv->flags & NFTA_FIB_F_IIF)
-		fl4.flowi4_l3mdev = l3mdev_master_ifindex_rcu(oif);
-
 	if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
 	    nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
 		nft_fib_store_result(dest, priv, nft_in(pkt));
diff --git a/net/ipv6/netfilter/nft_fib_ipv6.c b/net/ipv6/netfilter/nft_fib_ipv6.c
index 36dc14b34388..c9f1634b3838 100644
--- a/net/ipv6/netfilter/nft_fib_ipv6.c
+++ b/net/ipv6/netfilter/nft_fib_ipv6.c
@@ -41,8 +41,6 @@ static int nft_fib6_flowi_init(struct flowi6 *fl6, const struct nft_fib *priv,
 	if (ipv6_addr_type(&fl6->daddr) & IPV6_ADDR_LINKLOCAL) {
 		lookup_flags |= RT6_LOOKUP_F_IFACE;
 		fl6->flowi6_oif = get_ifindex(dev ? dev : pkt->skb->dev);
-	} else if (priv->flags & NFTA_FIB_F_IIF) {
-		fl6->flowi6_l3mdev = l3mdev_master_ifindex_rcu(dev);
 	}
 
 	if (ipv6_addr_type(&fl6->saddr) & IPV6_ADDR_UNICAST)
@@ -75,6 +73,8 @@ static u32 __nft_fib6_eval_type(const struct nft_fib *priv,
 	else if (priv->flags & NFTA_FIB_F_OIF)
 		dev = nft_out(pkt);
 
+	fl6.flowi6_l3mdev = l3mdev_master_ifindex_rcu(dev);
+
 	nft_fib6_flowi_init(&fl6, priv, pkt, dev, iph);
 
 	if (dev && nf_ipv6_chk_addr(nft_net(pkt), &fl6.daddr, dev, true))
@@ -165,6 +165,7 @@ void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
 		.flowi6_iif = LOOPBACK_IFINDEX,
 		.flowi6_proto = pkt->tprot,
 		.flowi6_uid = sock_net_uid(nft_net(pkt), NULL),
+		.flowi6_l3mdev = l3mdev_master_ifindex_rcu(nft_in(pkt)),
 	};
 	struct rt6_info *rt;
 	int lookup_flags;
-- 
2.30.2