Re: [syzbot] general protection fault in bpf_skb_cgroup_id

[Daniel Borkmann <daniel@iogearbox.net>]

On 9/17/21 11:06 PM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kern..
> git tree:       bpf
> console output: https://syzkaller.appspot.com/x/log.txt?x=15089853300000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c31c0936547df9ea
> dashboard link: https://syzkaller.appspot.com/bug?extid=33f36d0754d4c5c0e102
> 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=14dbd7ed300000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1586f83b300000
> 
> Bisection is inconclusive: the first bad commit could be any of:
> 
> 0e6491b55970 bpf: Add oversize check before call kvcalloc()
> 2f1aaf3ea666 bpf, mm: Fix lockdep warning triggered by stack_map_get_build_id_offset()
> 8520e224f547 bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
> 3a029e1f3d6e selftests/bpf: Fix build of task_pt_regs test for arm64
> d8079d8026f8 bpf, selftests: Add cgroup v1 net_cls classid helpers
> 43d2b88c29f2 bpf, selftests: Add test case for mixed cgroup v1/v2
> 49ca6153208f bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause
> 2865ba82476a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16b5ccdd300000

I'll take a look at the report.

Thanks,
Daniel