On 05/06/2015 06:42 PM, Eric Dumazet wrote:
> On Thu, 2015-05-07 at 00:04 +0200, Wolfgang Walter wrote:
>> Am Mittwoch, 6. Mai 2015, 12:10:00 schrieb Eric Dumazet:
>>> On Wed, 2015-05-06 at 11:15 -0700, Cong Wang wrote:
>>>> (Cc'ing netdev.)
>>>>
>>>> On Sat, May 2, 2015 at 5:29 AM, Wolfgang Walter <li...@stwm.de> wrote:
>>>>> Am Samstag, 2. Mai 2015, 02:16:36 schrieb Wolfgang Walter:
>>>>>> Hello,
>>>>>>
>>>>>> kernel 4.0 (and 4.0.1) crashes immediately when I use traceroute6 with
>>>>>> an
>>>>>> isatap-tunnel.
>>>>>
>>>>> I did some further tests. To trigger the crash you need
>>>>>
>>>>> * isatap-tunnel (probably any sit-tunnel will do it)
>>>>> * raw-socket
>>>>> * udp
>>>>>
>>>>> Using icmpv6 or tcp i.e. does not trigger it.
>>>>
>>>> Do you have a script to reproduce it?
>>>>
>>>>
>>>> Thanks for the bug report!
>>>> --
>>>
>>> Please Wolfgang try to revert 32dce968dd987adfb0c00946d78dad9154f64759
>>> ("ipv6: Allow for partial checksums on non-ufo packets")
>>
>> Indeed, that fixes the problem.
>
> Yes, setting skb->csum to 0 is clearly wrong for CHECKSUM_PARTIAL
>
> Would you try :
>
> diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
> index
> 7fde1f265c90e90f16291e6c861b6e242111c25b..694ae630e1ca67e25ab1e5f6dd0b3597db3669b0
> 100644
> --- a/net/ipv6/ip6_output.c
> +++ b/net/ipv6/ip6_output.c
> @@ -1416,6 +1416,10 @@ alloc_new_skb:
> data += fragheaderlen;
> skb->transport_header = (skb->network_header +
> fragheaderlen);
> + if (csummode == CHECKSUM_PARTIAL) {
> + skb->csum_start = skb_transport_header(skb) -
> skb->head;
> + skb->csum_offset = offsetof(struct udphdr,
> check);
> + }
> if (fraggap) {
> skb->csum = skb_copy_and_csum_bits(
> skb_prev, maxfraglen,
>
>
>
So why is this not an issue in __ip_append_data()?
-vlad
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
