Re: general protection fault in process_one_work

[Ido Schimmel]

On Tue, Oct 29, 2019 at 09:43:27AM +0100, Dmitry Vyukov wrote:
> On Tue, Oct 29, 2019 at 9:38 AM syzbot
> <syzbot+9ed8f68ab30761f3678e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    38207291 bpf: Prepare btf_ctx_access for non raw_tp use case
> > git tree:       bpf-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14173c0f600000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=41648156aa09be10
> > dashboard link: https://syzkaller.appspot.com/bug?extid=9ed8f68ab30761f3678e
> > 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@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> +JiÅÃ PÃrko, this seems to be related to netdevsim.

Will check it.

> 
> > 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 ef
> > 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:0000000000000000
> > 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 ef
> > 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:0000000000000000
> > 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@xxxxxxxxxxxxxxxxx
> >
> > syzbot will keep track of this bug report. See:
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> >
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