From: David Ahern <dsahern@gmail.com>
Date: Thu, 1 Aug 2019 21:36:35 +0000 (-0700)
Subject: ipv6: Fix unbalanced rcu locking in rt6_update_exception_stamp_rt
X-Git-Tag: v5.3-rc4~36^2~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cff6a327d78b05c98e0d1c4be77225ea2c0bfe8e;p=thirdparty%2Fkernel%2Flinux.git

ipv6: Fix unbalanced rcu locking in rt6_update_exception_stamp_rt

The nexthop path in rt6_update_exception_stamp_rt needs to call
rcu_read_unlock if it fails to find a fib6_nh match rather than
just returning.

Fixes: e659ba31d806 ("ipv6: Handle all fib6_nh in a nexthop in exception handling")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index e49fec767a10a..fd059e08785ab 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1951,7 +1951,7 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 		nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
 
 		if (!arg.match)
-			return;
+			goto unlock;
 		fib6_nh = arg.match;
 	} else {
 		fib6_nh = from->fib6_nh;