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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Anton Protopopov <a.s.protopopov@gmail.com>,
        =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>,
        David Ahern <dsahern@gmail.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 432/639] bpf: fix the check that forwarding is enabled in bpf_ipv6_fib_lookup
Date:   Fri, 24 Jan 2020 10:30:02 +0100
Message-Id: <20200124093141.159167686@linuxfoundation.org>
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From: Anton Protopopov <a.s.protopopov@gmail.com>

[ Upstream commit 56f0f84e69c7a7f229dfa524b13b0ceb6ce9b09e ]

The bpf_ipv6_fib_lookup function should return BPF_FIB_LKUP_RET_FWD_DISABLED
when forwarding is disabled for the input device.  However instead of checking
if forwarding is enabled on the input device, it checked the global
net->ipv6.devconf_all->forwarding flag.  Change it to behave as expected.

Fixes: 87f5fc7e48dd ("bpf: Provide helper to do forwarding lookups in kernel FIB table")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/core/filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 91b9502619757..9daf1a4118b51 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4367,7 +4367,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
 		return -ENODEV;
 
 	idev = __in6_dev_get_safely(dev);
-	if (unlikely(!idev || !net->ipv6.devconf_all->forwarding))
+	if (unlikely(!idev || !idev->cnf.forwarding))
 		return BPF_FIB_LKUP_RET_FWD_DISABLED;
 
 	if (flags & BPF_FIB_LOOKUP_OUTPUT) {
-- 
2.20.1