From 5e0115e500fe9dd2ca11e6f92db9123204f1327a Mon Sep 17 00:00:00 2001 From: Brian Haley Date: Wed, 13 Aug 2008 01:58:57 -0700 Subject: [PATCH] ipv6: Fix OOPS, ip -f inet6 route get fec0::1, linux-2.6.26, ip6_route_output, rt6_fill_node+0x175 Alexey Dobriyan wrote: > On Thu, Aug 07, 2008 at 07:00:56PM +0200, John Gumb wrote: >> Scenario: no ipv6 default route set. > >> # ip -f inet6 route get fec0::1 >> >> BUG: unable to handle kernel NULL pointer dereference at 00000000 >> IP: [] rt6_fill_node+0x175/0x3b0 >> EIP is at rt6_fill_node+0x175/0x3b0 > > 0xffffffff80424dd3 is in rt6_fill_node (net/ipv6/route.c:2191). > 2186 } else > 2187 #endif > 2188 NLA_PUT_U32(skb, RTA_IIF, iif); > 2189 } else if (dst) { > 2190 struct in6_addr saddr_buf; > 2191 ====> if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev, > ^^^^^^^^^^^^^^^^^^^^^^^^ > NULL > > 2192 dst, 0, &saddr_buf) == 0) > 2193 NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); > 2194 } The commit that changed this can't be reverted easily, but the patch below works for me. Fix NULL de-reference in rt6_fill_node() when there's no IPv6 input device present in the dst entry. Signed-off-by: Brian Haley Signed-off-by: David S. Miller --- net/ipv6/route.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 5a3e87e4b18..41b165ffb36 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2187,8 +2187,9 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt, #endif NLA_PUT_U32(skb, RTA_IIF, iif); } else if (dst) { + struct inet6_dev *idev = ip6_dst_idev(&rt->u.dst); struct in6_addr saddr_buf; - if (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev, + if (ipv6_dev_get_saddr(idev ? idev->dev : NULL, dst, 0, &saddr_buf) == 0) NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); } -- 2.41.1