From: David Miller <davem@davemloft.net>
To: liuhangbin@gmail.com
Cc: netdev@vger.kernel.org, sbrivio@redhat.com, wenxu@ucloud.cn,
ast@fb.com, eric.dumazet@gmail.com, ja@ssi.bg
Subject: Re: [PATCHv4 0/2] fix dev null pointer dereference when send packets larger than mtu in collect_md mode
Date: Sat, 24 Aug 2019 14:51:01 -0700 (PDT) [thread overview]
Message-ID: <20190824.145101.762776744197266351.davem@davemloft.net> (raw)
In-Reply-To: <20190822141949.29561-1-liuhangbin@gmail.com>
From: Hangbin Liu <liuhangbin@gmail.com>
Date: Thu, 22 Aug 2019 22:19:47 +0800
> When we send a packet larger than PMTU, we need to reply with
> icmp_send(ICMP_FRAG_NEEDED) or icmpv6_send(ICMPV6_PKT_TOOBIG).
>
> But with collect_md mode, kernel will crash while accessing the dst dev
> as __metadata_dst_init() init dst->dev to NULL by default. Here is what
> the code path looks like, for GRE:
...
> We could not fix it in __metadata_dst_init() as there is no dev supplied.
> Look in to the __icmp_send()/decode_session{4,6} code we could find the dst
> dev is actually not needed. In __icmp_send(), we could get the net by skb->dev.
> For decode_session{4,6}, as it was called by xfrm_decode_session_reverse()
> in this scenario, the oif is not used by
> fl4->flowi4_oif = reverse ? skb->skb_iif : oif;
>
> The reproducer is easy:
...
Series applied, and queued up for -stable, thanks!
prev parent reply other threads:[~2019-08-24 21:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 6:09 [PATCH net] tunnel: fix dev null pointer dereference when send pkg larger than mtu in collect_md mode Hangbin Liu
2019-08-15 9:16 ` Eric Dumazet
2019-08-16 3:24 ` Hangbin Liu
2019-08-16 4:01 ` Hangbin Liu
2019-08-16 8:23 ` Eric Dumazet
2019-08-16 10:51 ` Hangbin Liu
2019-08-19 7:53 ` [PATCHv2 0/2] " Hangbin Liu
2019-08-19 7:53 ` [PATCH 1/2] ipv4/icmp: fix rt dst dev null pointer dereference Hangbin Liu
2019-08-21 16:11 ` Julian Anastasov
2019-08-19 7:53 ` [PATCH 2/2] xfrm/xfrm_policy: fix dst dev null pointer dereference in collect_md mode Hangbin Liu
2019-08-20 19:20 ` [PATCHv2 0/2] fix dev null pointer dereference when send pkg larger than mtu " David Miller
2019-08-21 2:09 ` [PATCHv3 0/2] fix dev null pointer dereference when send packets " Hangbin Liu
2019-08-21 2:09 ` [PATCHv3 1/2] ipv4/icmp: fix rt dst dev null pointer dereference Hangbin Liu
2019-08-21 2:09 ` [PATCHv3 2/2] xfrm/xfrm_policy: fix dst dev null pointer dereference in collect_md mode Hangbin Liu
2019-08-22 14:19 ` [PATCHv4 0/2] fix dev null pointer dereference when send packets larger than mtu " Hangbin Liu
2019-08-22 14:19 ` [PATCHv4 net 1/2] ipv4/icmp: fix rt dst dev null pointer dereference Hangbin Liu
2019-08-22 18:46 ` Julian Anastasov
2019-08-23 22:32 ` Jonathan Lemon
2019-08-22 14:19 ` [PATCHv4 net 2/2] xfrm/xfrm_policy: fix dst dev null pointer dereference in collect_md mode Hangbin Liu
2019-08-23 22:30 ` Jonathan Lemon
2019-08-24 21:51 ` David Miller [this message]
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