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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Tue, 29 Oct 2019 09:43:27 +0100
Message-ID: <CACT4Y+b7nkRO_Q6X3sTWbGU5Y6bGuZPmKzoPL2uoFpA4KCP2hw@mail.gmail.com>
Subject: Re: general protection fault in process_one_work
To:     syzbot <syzbot+9ed8f68ab30761f3678e@syzkaller.appspotmail.com>,
        Jiri Pirko <jiri@mellanox.com>
Cc:     Alexei Starovoitov <ast@kernel.org>, bpf <bpf@vger.kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        David Miller <davem@davemloft.net>,
        Jakub Kicinski <jakub.kicinski@netronome.com>,
        Martin KaFai Lau <kafai@fb.com>,
        LKML <linux-kernel@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        Song Liu <songliubraving@fb.com>,
        syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
        Yonghong Song <yhs@fb.com>
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On Tue, Oct 29, 2019 at 9:38 AM syzbot
<syzbot+9ed8f68ab30761f3678e@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    38207291 bpf: Prepare btf_ctx_access for non raw_tp use c=
ase
> git tree:       bpf-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=3D14173c0f60000=
0
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3D41648156aa09b=
e10
> dashboard link: https://syzkaller.appspot.com/bug?extid=3D9ed8f68ab30761f=
3678e
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit=
:
> Reported-by: syzbot+9ed8f68ab30761f3678e@syzkaller.appspotmail.com

+Ji=C5=99=C3=AD P=C3=ADrko, this seems to be related to netdevsim.

> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] PREEMPT SMP KASAN
> CPU: 1 PID: 9149 Comm: kworker/1:3 Not tainted 5.4.0-rc1+ #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Workqueue: events nsim_dev_trap_report_work
> RIP: 0010:nsim_dev_trap_report_work+0xc4/0xaf0
> drivers/net/netdevsim/dev.c:409
> Code: 89 45 d0 0f 84 8b 07 00 00 49 bc 00 00 00 00 00 fc ff df e8 3e ae e=
f
> fc 48 8b 45 d0 48 05 68 01 00 00 48 89 45 90 48 c1 e8 03 <42> 80 3c 20 00
> 0f 85 b1 09 00 00 48 8b 45 d0 48 8b 98 68 01 00 00
> RSP: 0018:ffff88806c98fc90 EFLAGS: 00010a06
> RAX: 1bd5a0000000004d RBX: 0000000000000000 RCX: ffffffff84836e22
> RDX: 0000000000000000 RSI: ffffffff84836db2 RDI: 0000000000000001
> RBP: ffff88806c98fd30 R08: ffff88806c9863c0 R09: ffffed100d75f3d9
> R10: ffffed100d75f3d8 R11: ffff88806baf9ec7 R12: dffffc0000000000
> R13: ffff88806baf9ec0 R14: ffff8880a9a13900 R15: ffff8880ae934500
> FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000=
000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007efdd0c9e000 CR3: 000000009cc1b000 CR4: 00000000001406e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>   process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
>   worker_thread+0x98/0xe40 kernel/workqueue.c:2415
>   kthread+0x361/0x430 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> Modules linked in:
> ---[ end trace ba29cd1c27f63d86 ]---
> RIP: 0010:nsim_dev_trap_report_work+0xc4/0xaf0
> drivers/net/netdevsim/dev.c:409
> Code: 89 45 d0 0f 84 8b 07 00 00 49 bc 00 00 00 00 00 fc ff df e8 3e ae e=
f
> fc 48 8b 45 d0 48 05 68 01 00 00 48 89 45 90 48 c1 e8 03 <42> 80 3c 20 00
> 0f 85 b1 09 00 00 48 8b 45 d0 48 8b 98 68 01 00 00
> RSP: 0018:ffff88806c98fc90 EFLAGS: 00010a06
> RAX: 1bd5a0000000004d RBX: 0000000000000000 RCX: ffffffff84836e22
> RDX: 0000000000000000 RSI: ffffffff84836db2 RDI: 0000000000000001
> RBP: ffff88806c98fd30 R08: ffff88806c9863c0 R09: ffffed100d75f3d9
> R10: ffffed100d75f3d8 R11: ffff88806baf9ec7 R12: dffffc0000000000
> R13: ffff88806baf9ec0 R14: ffff8880a9a13900 R15: ffff8880ae934500
> FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000=
000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007efdd0c9e000 CR3: 000000009cc1b000 CR4: 00000000001406e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
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