From: Eric Dumazet <edumazet@google.com>
Date: Sat, 15 Aug 2015 17:54:07 +0000 (-0700)
Subject: ipv4: fix refcount leak in fib_check_nh()
X-Git-Tag: firefly_0821_release~176^2~1159^2~164
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1e3136789975f03e461798149309034e5213c1b4;p=firefly-linux-kernel-4.4.55.git

ipv4: fix refcount leak in fib_check_nh()

fib_lookup() forces FIB_LOOKUP_NOREF flag, while fib_table_lookup()
does not.

This patch solves the typical message at reboot time or device
dismantle :

unregister_netdevice: waiting for eth0 to become free. Usage count = 4

Fixes: 3bfd847203c6 ("net: Use passed in table for nexthop lookups")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsa@cumulusnetworks.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index b7f1d20a9615..c8025851dac7 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -708,7 +708,8 @@ static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
 
 			if (tbl)
 				err = fib_table_lookup(tbl, &fl4, &res,
-						   FIB_LOOKUP_IGNORE_LINKSTATE);
+						       FIB_LOOKUP_IGNORE_LINKSTATE |
+						       FIB_LOOKUP_NOREF);
 			else
 				err = fib_lookup(net, &fl4, &res,
 						 FIB_LOOKUP_IGNORE_LINKSTATE);