Messages in this thread | | | Date | Mon, 2 Oct 2017 18:34:02 +0100 | From | Mark Rutland <> | Subject | Re: v4.14-rc2/arm64 kernel BUG at net/core/skbuff.c:2626 |
| |
On Mon, Oct 02, 2017 at 10:27:15AM -0700, Eric Dumazet wrote: > On Mon, Oct 2, 2017 at 10:21 AM, Mark Rutland <mark.rutland@arm.com> wrote: > > On Mon, Oct 02, 2017 at 07:48:28AM -0700, Eric Dumazet wrote: > >> Please try the following fool proof patch. > >> > >> This is what I had in my local tree back in August but could not > >> conclude on the syzkaller bug I was working on. > >> > >> diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c > >> index 681e33998e03b609fdca83a83e0fc62a3fee8c39..e51d777797a927058760a1ab7af00579f7488cb5 100644 > >> --- a/net/ipv4/icmp.c > >> +++ b/net/ipv4/icmp.c > >> @@ -732,7 +732,8 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info) > >> room = 576; > >> room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen; > >> room -= sizeof(struct icmphdr); > >> - > >> + if (room < 0) > >> + goto ende; > >> icmp_param.data_len = skb_in->len - icmp_param.offset; > >> if (icmp_param.data_len > room) > >> icmp_param.data_len = room; > >> > > > > Unfortuantely, with this applied I still see the issue. > > > > Syzkaller came up with a minimized reproducer [1], which can trigger the > > issue near instantly under syz-execprog. If there's anything that would > > help to narrow this down, I'm more than happy to give it a go. > > > > Thanks, > > Mark. > > > > [1] https://www.kernel.org/pub/linux/kernel/people/mark/bugs/20171002-skb_clone-misaligned-atomic/syzkaller.repro > > Note that I was not trying to address the misaligned stuff.
Aargh, I put the reproducer in the wrong folder thanks to tab-completing my kup command. :/
The reproducer linked above is for the kernel BUG at net/core/skbuff.c:2626.
I've uploaded a copy into the relevant bug directory [1], but that'll take a little while to sync out. I'll drop it from the misalignment bug folder once that's visible to all.
Sorry about that!
Thanks, Mark.
[1] https://www.kernel.org/pub/linux/kernel/people/mark/bugs/20171002-skbuff-bug/
| |