Re: [PATCH net v2] ipv6: the entire IPv6 header chain must fit the first fragment

2018-03-25 Thread David Miller
From: Paolo Abeni Date: Fri, 23 Mar 2018 14:47:30 +0100 > While building ipv6 datagram we currently allow arbitrary large > extheaders, even beyond pmtu size. The syzbot has found a way > to exploit the above to trigger the following splat: ... > As stated by RFC 7112 section 5: > >When a h

Re: [PATCH net v2] ipv6: the entire IPv6 header chain must fit the first fragment

2018-03-23 Thread Eric Dumazet
On 03/23/2018 06:47 AM, Paolo Abeni wrote: > While building ipv6 datagram we currently allow arbitrary large > extheaders, even beyond pmtu size. The syzbot has found a way > to exploit the above to trigger the following splat: > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-by: syzbot+9

[PATCH net v2] ipv6: the entire IPv6 header chain must fit the first fragment

2018-03-23 Thread Paolo Abeni
While building ipv6 datagram we currently allow arbitrary large extheaders, even beyond pmtu size. The syzbot has found a way to exploit the above to trigger the following splat: kernel BUG at ./include/linux/skbuff.h:2073! invalid opcode: [#1] SMP KASAN Dumping ftrace buffer: (ftrace buf