[Devel] [PATCH RH7 03/10] netfilter: nft_fib_ipv4: initialize *dest to zero

[Pavel Tikhomirov]

From: Liping Zhang <zlpnobody at gmail.com>

Otherwise, if fib lookup fail, *dest will be filled with garbage value,
so reverse path filtering will not work properly:
 # nft add rule x prerouting fib saddr oif eq 0 drop

Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Liping Zhang <zlpnobody at gmail.com>
Acked-by: Florian Westphal <fw at strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>

https://jira.sw.ru/browse/PSBM-125002
(cherry picked from commit e0ffdbc78d84e1da090f03ab62da3def0e65159e)
Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 net/ipv4/netfilter/nft_fib_ipv4.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/netfilter/nft_fib_ipv4.c b/net/ipv4/netfilter/nft_fib_ipv4.c
index 976a73bbe7ab8..1c82b94a88158 100644
--- a/net/ipv4/netfilter/nft_fib_ipv4.c
+++ b/net/ipv4/netfilter/nft_fib_ipv4.c
@@ -122,6 +122,8 @@ void nft_fib4_eval(const struct nft_expr *expr, struct nft_regs *regs,
 		fl4.saddr = get_saddr(iph->daddr);
 	}
 
+	*dest = 0;
+
 	if (fib_lookup(nft_net(pkt), &fl4, &res))
 		return;
 
-- 
2.26.2