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.
Thanks, I'll give this a go shortly. I'm currently minimizing the Syzkaller log so that I can trigger the issue more quickly (and have some confidence in a Tested-by)! Thanks, Mark. > 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; > > >
