From db84df7ce1c2abbe96b772c14685018f5cdd86b5 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Mon, 20 May 2019 11:07:29 +0200
Subject: [PATCH] fib_rules: fix error in backport of e9919a24d302 ("fib_rules:
 return 0...")

When commit e9919a24d302 ("fib_rules: return 0 directly if an exactly
same rule exists when NLM_F_EXCL not supplied") was backported to 4.9.y,
it changed the logic a bit as err should have been reset before exiting
the test, like it happens in the original logic.

If this is not set, errors happen :(

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reported-by: David Ahern <dsahern@gmail.com>
Reported-by: Florian Westphal <fw@strlen.de>
Cc: Hangbin Liu <liuhangbin@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/fib_rules.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 25c25e85ca06..268e32005273 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -487,6 +487,7 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh)
 	}
 
 	if (rule_exists(ops, frh, tb, rule)) {
+		err = 0;
 		if (nlh->nlmsg_flags & NLM_F_EXCL)
 			err = -EEXIST;
 		goto errout_free;