From 6de88839e47b4cb4dc97b095a2a89399fbec8a23 Mon Sep 17 00:00:00 2001
From: Stephen Hemminger <shemminger@vyatta.com>
Date: Tue, 24 May 2011 13:50:52 -0400
Subject: [PATCH] dst: catch uninitialized metrics

[ Upstream commit 1f37070d3ff325827c6213e51b57f21fd5ac9d05 ]

Catch cases where dst_metric_set() and other functions are called
but _metrics is NULL.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 include/net/dst.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/net/dst.h b/include/net/dst.h
index 75b95df4afe71..b3ad020faec52 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -120,6 +120,8 @@ static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
 {
 	unsigned long p = dst->_metrics;
 
+	BUG_ON(!p);
+
 	if (p & DST_METRICS_READ_ONLY)
 		return dst->ops->cow_metrics(dst, p);
 	return __DST_METRICS_PTR(p);
-- 
2.47.2