Messages in this thread | | | Subject | Re: general protection fault in fib_dump_info (2) | From | Nikolay Aleksandrov <> | Date | Fri, 21 Aug 2020 19:00:18 +0300 |
| |
On 8/21/20 6:27 PM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: da2968ff Merge tag 'pci-v5.9-fixes-1' of git://git.kernel... > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=137316ca900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a0437fdd630bee11 > dashboard link: https://syzkaller.appspot.com/bug?extid=a61aa19b0c14c8770bd9 > compiler: gcc (GCC) 10.1.0-syz 20200507 > userspace arch: i386 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12707051900000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1150a046900000 > > The issue was bisected to: > > commit 0b5e2e39739e861fa5fc84ab27a35dbe62a15330 > Author: David Ahern <dsahern@gmail.com> > Date: Tue May 26 18:56:16 2020 +0000 > > nexthop: Expand nexthop_is_multipath in a few places >
This seems like a much older bug to me, the code allows to pass 0 groups and thus we end up without any nh_grp_entry pointers. I reproduced it with a modified iproute2 that sends an empty NHA_GROUP and then just uses the new nexthop in any way (e.g. add a route with it). This is the same bug as the earlier report for: "general protection fault in fib_check_nexthop"
I have a patch but I'll be able to send it tomorrow.
Cheers, Nik
| |