Re: [PATCH] net/ipv4: swap flow ports when validating source
From: David Ahern <hidden>
Date: 2021-06-22 01:23:49
On 6/21/21 9:17 AM, Wang Shanker wrote:
When doing source address validation, the flowi4 struct used for
fib_lookup should be in the reverse direction to the given skb.
fl4_dport and fl4_sport returned by fib4_rules_early_flow_dissect
should thus be swapped.
Fixes: 5a847a6 ("net/ipv4: Initialize proto and ports in flow struct")I believe the hash should be 12 chars: 5a847a6e1477
quoted hunk ↗ jump to hunk
Signed-off-by: Miao Wang <redacted> --- net/ipv4/fib_frontend.c | 2 ++ 1 file changed, 2 insertions(+)diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 84bb707bd88d..647bceab56c2 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c@@ -371,6 +371,8 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, fl4.flowi4_proto = 0; fl4.fl4_sport = 0; fl4.fl4_dport = 0; + } else { + swap(fl4.fl4_sport, fl4.fl4_dport); } if (fib_lookup(net, &fl4, &res, 0))
Reviewed-by: David Ahern <dsahern@kernel.org>