[PATCH 4.9 36/66] ipv6: ip6_make_skb() needs to clear cork.base.dst

From: Greg Kroah-Hartman
Date: Mon Jan 29 2018 - 15:32:40 EST


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

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

From: Eric Dumazet <edumazet@xxxxxxxxxx>


[ Upstream commit 95ef498d977bf44ac094778fd448b98af158a3e6 ]

In my last patch, I missed fact that cork.base.dst was not initialized
in ip6_make_skb() :

If ip6_setup_cork() returns an error, we might attempt a dst_release()
on some random pointer.

Fixes: 862c03ee1deb ("ipv6: fix possible mem leaks in ipv6_make_skb()")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_output.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1800,6 +1800,7 @@ struct sk_buff *ip6_make_skb(struct sock
cork.base.flags = 0;
cork.base.addr = 0;
cork.base.opt = NULL;
+ cork.base.dst = NULL;
v6_cork.opt = NULL;
err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
if (err) {