On 06/11/2018 11:52 AM, Dmitry Vyukov wrote: > On Mon, Jun 11, 2018 at 11:42 AM, Daniel Borkmann <dan...@iogearbox.net> > wrote: >> On 06/10/2018 05:27 PM, syzbot wrote: >>> Hello, >>> >>> syzbot found the following crash on: >>> >>> HEAD commit: a16afaf7928b Merge tag 'for-v4.18' of git://git.kernel.org.. >>> git tree: upstream >>> console output: https://syzkaller.appspot.com/x/log.txt?x=1338f6bf800000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=314f2150f36c16ca >>> dashboard link: https://syzkaller.appspot.com/bug?extid=d2d729bdde65dee3eae6 >>> compiler: gcc (GCC) 8.0.1 20180413 (experimental) >>> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1173381f800000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=171f90cf800000 >>> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>> Reported-by: syzbot+d2d729bdde65dee3e...@syzkaller.appspotmail.com >> >> #syz fix: bpf: reject passing modified ctx to helper functions > > On a related note, it seems that it still can unwind past > bpf_skb_change_proto. I think the "net.core.bpf_jit_kallsyms = 1" > sysctl should have been reached syzbot by the time of crash. Are you > sure that's the only thing requires? We are using frame pointer > unwinder just in case.
Nah, I know what happened; just sent a PR fix for syzkaller. Thanks, Daniel
