Re: [syzbot] [bpf?] [net?] general protection fault in bpf_struct_ops_link_create

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 3/24/23 7:11 AM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    226bc6ae6405 Merge branch 'Transit between BPF TCP congest..
> git tree:       bpf-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=139c727ac80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=cab35c936731a347
> dashboard link: https://syzkaller.appspot.com/bug?extid=71ccc0fe37abb458406b
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11ef67a1c80000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=119c20fec80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/ac055f681ed7/disk-226bc6ae.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/3895cc8a51d2/vmlinux-226bc6ae.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/1b18bb9fae05/bzImage-226bc6ae.xz
>
> The issue was bisected to:
>
> commit 68b04864ca425d1894c96b8141d4fba1181f11cb
> Author: Kui-Feng Lee <kuifeng@xxxxxxxx>
> Date:   Thu Mar 23 03:24:00 2023 +0000
>
>      bpf: Create links for BPF struct_ops maps.
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=116731b1c80000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=136731b1c80000
> console output: https://syzkaller.appspot.com/x/log.txt?x=156731b1c80000

Kui-Feng, please take a look & fix.

> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+71ccc0fe37abb458406b@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 68b04864ca42 ("bpf: Create links for BPF struct_ops maps.")

Thanks,
Daniel