Re: [syzbot] WARNING in btf_type_id_size

[Stanislav Fomichev]

On Sat, Oct 15, 2022 at 11:52 PM syzbot
<syzbot+6280ebbcdba3e0c14fde@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    0326074ff465 Merge tag 'net-next-6.1' of git://git.kernel...
> git tree:       bpf
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=1376ba52880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=796b7c2847a6866a
> dashboard link: https://syzkaller.appspot.com/bug?extid=6280ebbcdba3e0c14fde
> 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=15e182aa880000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1677bfcc880000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/7cc67ced256d/disk-0326074f.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/86a7be29267c/vmlinux-0326074f.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+6280ebbcdba3e0c14fde@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 3609 at kernel/bpf/btf.c:1946 btf_type_id_size+0x2d5/0x9d0 kernel/bpf/btf.c:1946
> Modules linked in:
> CPU: 0 PID: 3609 Comm: syz-executor361 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
> RIP: 0010:btf_type_id_size+0x2d5/0x9d0 kernel/bpf/btf.c:1946
> Code: ef e8 7f 8e e4 ff 41 83 ff 0b 77 28 f6 44 24 10 18 75 3f e8 6d 91 e4 ff 44 89 fe bf 0e 00 00 00 e8 20 8e e4 ff e8 5b 91 e4 ff <0f> 0b 45 31 f6 e9 98 02 00 00 41 83 ff 12 74 18 e8 46 91 e4 ff 44
> RSP: 0018:ffffc90003cefb40 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
> RDX: ffff8880259c0000 RSI: ffffffff81968415 RDI: 0000000000000005
> RBP: ffff88801270ca00 R08: 0000000000000005 R09: 000000000000000e
> R10: 0000000000000011 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000011 R14: ffff888026ee6424 R15: 0000000000000011
> FS:  000055555641b300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000f2e258 CR3: 000000007110e000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  btf_func_proto_check kernel/bpf/btf.c:4447 [inline]
>  btf_check_all_types kernel/bpf/btf.c:4723 [inline]
>  btf_parse_type_sec kernel/bpf/btf.c:4752 [inline]
>  btf_parse kernel/bpf/btf.c:5026 [inline]
>  btf_new_fd+0x1926/0x1e70 kernel/bpf/btf.c:6892
>  bpf_btf_load kernel/bpf/syscall.c:4324 [inline]
>  __sys_bpf+0xb7d/0x4cf0 kernel/bpf/syscall.c:5010
>  __do_sys_bpf kernel/bpf/syscall.c:5069 [inline]
>  __se_sys_bpf kernel/bpf/syscall.c:5067 [inline]
>  __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5067
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f0fbae41c69
> Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffc8aeb6228 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0fbae41c69
> RDX: 0000000000000020 RSI: 0000000020000140 RDI: 0000000000000012
> RBP: 00007f0fbae05e10 R08: 0000000000000000 R09: 0000000000000000
> R10: 00000000ffffffff R11: 0000000000000246 R12: 00007f0fbae05ea0
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
>  </TASK>

Will be addressed by
https://lore.kernel.org/bpf/d1379e3f-a64d-8c27-9b77-f6de085ce498@xxxxxxxx/T/#u


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