netdev - Re: [PATCH net-next] packet: fix panic in __packet_set_timestamp on tpacket

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <586E9A0F.1020002@iogearbox.net>
Date:   Thu, 05 Jan 2017 20:10:07 +0100
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Eric Dumazet <eric.dumazet@...il.com>
CC:     davem@...emloft.net, sowmini.varadhan@...cle.com,
        willemb@...gle.com, netdev@...r.kernel.org
Subject: Re: [PATCH net-next] packet: fix panic in __packet_set_timestamp
 on tpacket_v3 in tx mode

On 01/05/2017 07:27 PM, Eric Dumazet wrote:
> On Thu, 2017-01-05 at 02:34 +0100, Daniel Borkmann wrote:
[...]
>> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
>> index 7e39087..ddbda25 100644
>> --- a/net/packet/af_packet.c
>> +++ b/net/packet/af_packet.c
>> @@ -481,6 +481,9 @@ static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
>>   		h.h2->tp_nsec = ts.tv_nsec;
>>   		break;
>>   	case TPACKET_V3:
>> +		h.h3->tp_sec = ts.tv_sec;
>> +		h.h3->tp_nsec = ts.tv_nsec;
>> +		break;
>>   	default:
>>   		WARN(1, "TPACKET version not supported.\n");
>>   		BUG();
>
> Gosh. Can we also replace this BUG() into something less aggressive ?

There are currently 5 of these WARN() + BUG() constructs and 1 BUG()-only
for the 'default' TPACKET version spread all over af_packet, so probably
makes sense to rather make all of them less aggressive.

> diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
> index b9e1a13b4ba36a0bc7edf6a8c2c116c7d48c970c..0c0d268544787dcbef6601c5014e7d3836d16f96 100644
> --- a/net/packet/af_packet.c
> +++ b/net/packet/af_packet.c
> @@ -476,9 +476,11 @@ static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
>   		h.h2->tp_nsec = ts.tv_nsec;
>   		break;
>   	case TPACKET_V3:
> +		h.h3->tp_sec = ts.tv_sec;
> +		h.h3->tp_nsec = ts.tv_nsec;
> +		break;
>   	default:
> -		WARN(1, "TPACKET version not supported.\n");
> -		BUG();
> +		pr_err_once("TPACKET version %u not supported.\n", po->tp_version);
>   	}
>
>   	/* one flush is safe, as both fields always lie on the same cacheline */
>
>