[PATCH 4.9 040/109] libcxgb: fix error check for ip6_route_output()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Varun Prakash <varun@xxxxxxxxxxx>


[ Upstream commit a9a8cdb368d99bb655b5cdabea560446db0527cc ]

ip6_route_output() never returns NULL so
check dst->error instead of !dst.

Signed-off-by: Varun Prakash <varun@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/chelsio/libcxgb/libcxgb_cm.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/chelsio/libcxgb/libcxgb_cm.c
+++ b/drivers/net/ethernet/chelsio/libcxgb/libcxgb_cm.c
@@ -133,17 +133,15 @@ cxgb_find_route6(struct cxgb4_lld_info *
 		if (ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LINKLOCAL)
 			fl6.flowi6_oif = sin6_scope_id;
 		dst = ip6_route_output(&init_net, NULL, &fl6);
-		if (!dst)
-			goto out;
-		if (!cxgb_our_interface(lldi, get_real_dev,
-					ip6_dst_idev(dst)->dev) &&
-		    !(ip6_dst_idev(dst)->dev->flags & IFF_LOOPBACK)) {
+		if (dst->error ||
+		    (!cxgb_our_interface(lldi, get_real_dev,
+					 ip6_dst_idev(dst)->dev) &&
+		     !(ip6_dst_idev(dst)->dev->flags & IFF_LOOPBACK))) {
 			dst_release(dst);
-			dst = NULL;
+			return NULL;
 		}
 	}
 
-out:
 	return dst;
 }
 EXPORT_SYMBOL(cxgb_find_route6);