Re: WARNING: bad usercopy in corrupted (2)

[Matthew Wilcox]

On Sun, Nov 25, 2018 at 01:27:09PM -0800, Matthew Wilcox wrote:
> On Sun, Nov 25, 2018 at 07:30:04AM -0800, syzbot wrote:
> > Hello,
> > 
> > syzbot found the following crash on:
> > 
> > HEAD commit:    aea0a897af9e ptp: Fix pass zero to ERR_PTR() in ptp_clock_..
> > git tree:       net-next
> 
> If you found it on net-next, I'd suggets cc'ing linux-net ...

Uh.  I meant netdev.  Oops.

> > console output: https://syzkaller.appspot.com/x/log.txt?x=101b91d5400000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c36a72af2123e78a
> > dashboard link: https://syzkaller.appspot.com/bug?extid=d89b30c46434c433dbf8
> > compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=170f6a47400000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12e1df7b400000
> > 
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+d89b30c46434c433dbf8@xxxxxxxxxxxxxxxxxxxxxxxxx
> > 
> > ------------[ cut here ]------------
> > DEBUG_LOCKS_WARN_ON(!hlock->nest_lock)
> > ------------[ cut here ]------------
> > Bad or missing usercopy whitelist? Kernel memory overwrite attempt detected
> > to SLAB object 'task_struct' (offset 1432, size 2)!
> > WARNING: CPU: 1 PID: 38 at mm/usercopy.c:83 usercopy_warn+0xee/0x110
> > mm/usercopy.c:78
> > Kernel panic - not syncing: panic_on_warn set ...
> > list_add corruption. next->prev should be prev (ffff8881daf2d798), but was
> > 0b7e0c8e49cc0400. (next=ffff8881d9b4a4f0).
> > CPU: 1 PID: 38 Comm: ïïïÙïïïdïïïïïï Not tainted 4.20.0-rc3+ #312
> > ------------[ cut here ]------------
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > kernel BUG at lib/list_debug.c:25!
> > ------------[ cut here ]------------
> > invalid opcode: 0000 [#1] PREEMPT SMP KASAN
> > kernel BUG at mm/slab.c:4425!
> > CPU: 0 PID: 8652 Comm: syz-executor607 Not tainted 4.20.0-rc3+ #312
> > WARNING: CPU: 1 PID: 38 at kernel/rcu/tree_plugin.h:438
> > __rcu_read_unlock+0x266/0x2e0 kernel/rcu/tree_plugin.h:432
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > Modules linked in:
> > RIP: 0010:__list_add_valid.cold.2+0xf/0x2a lib/list_debug.c:23
> > CPU: 1 PID: 38 Comm: ïïïÙïïïdïïïïïï Not tainted 4.20.0-rc3+ #312
> > Code: d1 60 88 e8 a1 37 d2 fd 0f 0b 48 89 de 48 c7 c7 60 d1 60 88 e8 90 37
> > d2 fd 0f 0b 48 89 d9 48 c7 c7 20 d2 60 88 e8 7f 37 d2 fd <0f> 0b 48 89 f1 48
> > c7 c7 a0 d2 60 88 48 89 de e8 6b 37 d2 fd 0f 0b
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > RSP: 0000:ffff8881dae07588 EFLAGS: 00010082
> > usercopy: Kernel memory overwrite attempt detected to SLAB object
> > 'signal_cache' (offset 1328, size 23)!
> > RAX: 0000000000000075 RBX: ffff8881d9b4a4f0 RCX: 0000000000000000
> > ------------[ cut here ]------------
> > RDX: 0000000000000000 RSI: ffffffff8165eaf5 RDI: 0000000000000005
> > kernel BUG at mm/usercopy.c:102!
> > RBP: ffff8881dae075a0 R08: ffff8881d25ce100 R09: ffffed103b5c5020
> > R10: ffffed103b5c5020 R11: ffff8881dae28107 R12: ffff8881bd890230
> > R13: dffffc0000000000 R14: ffff8881dae07980 R15: ffff8881daf2d798
> > FS:  000000000083c880(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 00007fff14476600 CR3: 00000001d2a59000 CR4: 00000000001406f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> >  <IRQ>
> >  __list_add include/linux/list.h:60 [inline]
> >  list_add include/linux/list.h:79 [inline]
> >  list_move include/linux/list.h:171 [inline]
> >  detach_tasks kernel/sched/fair.c:7298 [inline]
> >  load_balance+0x1b8d/0x39a0 kernel/sched/fair.c:8731
> >  rebalance_domains+0x845/0xdc0 kernel/sched/fair.c:9109
> >  run_rebalance_domains+0x38d/0x500 kernel/sched/fair.c:9731
> >  __do_softirq+0x308/0xb7e kernel/softirq.c:292
> >  invoke_softirq kernel/softirq.c:373 [inline]
> >  irq_exit+0x17f/0x1c0 kernel/softirq.c:413
> >  exiting_irq arch/x86/include/asm/apic.h:536 [inline]
> >  smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061
> >  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804
> >  </IRQ>
> > RIP: 0033:0x4005dd
> > Code: c9 00 04 00 66 0f 1f 84 00 00 00 00 00 48 8b 05 f1 2e 2d 00 48 85 c0
> > 74 11 bf 3c e8 4b 00 b9 0e 00 00 00 48 89 c6 f3 a6 75 01 <c3> 48 89 c7 e9 9a
> > ec 01 00 66 2e 0f 1f 84 00 00 00 00 00 8b 05 4a
> > RSP: 002b:00007fff144765a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> > RAX: 0000000000000000 RBX: 0000000000000002 RCX: 00000000006d2190
> > RDX: 0000000000402410 RSI: 0000000000000000 RDI: 0000000000000000
> > RBP: 00000000006cc0a8 R08: 0000000000000000 R09: 0000000000000000
> > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> > R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000
> > Modules linked in:
> > ---[ end trace eeb5734c13709e17 ]---
> > invalid opcode: 0000 [#2] PREEMPT SMP KASAN
> > CPU: 1 PID: 38 Comm: ïïïÙïïïdïïïïïï Tainted: G      D           4.20.0-rc3+
> > #312
> > RIP: 0010:__list_add_valid.cold.2+0xf/0x2a lib/list_debug.c:23
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > Code: d1 60 88 e8 a1 37 d2 fd 0f 0b 48 89 de 48 c7 c7 60 d1 60 88 e8 90 37
> > d2 fd 0f 0b 48 89 d9 48 c7 c7 20 d2 60 88 e8 7f 37 d2 fd <0f> 0b 48 89 f1 48
> > c7 c7 a0 d2 60 88 48 89 de e8 6b 37 d2 fd 0f 0b
> > RIP: 0010:usercopy_abort+0xbb/0xbd mm/usercopy.c:90
> > RSP: 0000:ffff8881dae07588 EFLAGS: 00010082
> > Code: c0 e8 f7 dc b1 ff 48 8b 55 c0 49 89 d9 4d 89 f0 ff 75 c8 4c 89 e1 4c
> > 89 ee 48 c7 c7 80 d5 34 88 ff 75 d0 41 57 e8 e7 28 98 ff <0f> 0b e8 cc dc b1
> > ff e8 97 13 f5 ff 8b 95 e4 fe ff ff 4c 89 e1 31
> > RAX: 0000000000000075 RBX: ffff8881d9b4a4f0 RCX: 0000000000000000
> > RSP: 0018:ffff8881d9b49438 EFLAGS: 00010086
> > RDX: 0000000000000000 RSI: ffffffff8165eaf5 RDI: 0000000000000005
> > RAX: 0000000000000068 RBX: ffffffff88291020 RCX: 0000000000000000
> > RBP: ffff8881dae075a0 R08: ffff8881d25ce100 R09: ffffed103b5c5020
> > RDX: 0000000000000000 RSI: ffffffff8165eaf5 RDI: 0000000000000005
> > R10: ffffed103b5c5020 R11: ffff8881dae28107 R12: ffff8881bd890230
> > RBP: ffff8881d9b49490 R08: ffff8881d9b4a440 R09: ffffed103b5e3ef8
> > R13: dffffc0000000000 R14: ffff8881dae07980 R15: ffff8881daf2d798
> > R10: ffffed103b5e3ef8 R11: ffff8881daf1f7c7 R12: ffffffff8914da1d
> > FS:  000000000083c880(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000
> > R13: ffffffff8834d3e0 R14: ffffffff8834d320 R15: ffffffff8834d2e0
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > FS:  0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
> > CR2: 00007fff14476600 CR3: 00000001d2a59000 CR4: 00000000001406f0
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > CR2: 0000000000000130 CR3: 00000001d7880000 CR4: 00000000001406e0
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > Modules linked in:
> > ---[ end trace eeb5734c13709e18 ]---
> > RIP: 0010:__list_add_valid.cold.2+0xf/0x2a lib/list_debug.c:23
> > Code: d1 60 88 e8 a1 37 d2 fd 0f 0b 48 89 de 48 c7 c7 60 d1 60 88 e8 90 37
> > d2 fd 0f 0b 48 89 d9 48 c7 c7 20 d2 60 88 e8 7f 37 d2 fd <0f> 0b 48 89 f1 48
> > c7 c7 a0 d2 60 88 48 89 de e8 6b 37 d2 fd 0f 0b
> > RSP: 0000:ffff8881dae07588 EFLAGS: 00010082
> > RAX: 0000000000000075 RBX: ffff8881d9b4a4f0 RCX: 0000000000000000
> > RDX: 0000000000000000 RSI: ffffffff8165eaf5 RDI: 0000000000000005
> > RBP: ffff8881dae075a0 R08: ffff8881d25ce100 R09: ffffed103b5c5020
> > R10: ffffed103b5c5020 R11: ffff8881dae28107 R12: ffff8881bd890230
> > R13: dffffc0000000000 R14: ffff8881dae07980 R15: ffff8881daf2d798
> > FS:  0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000000000000130 CR3: 00000001d7880000 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:
> > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> > syzbot.
> > syzbot can test patches for this bug, for details see:
> > https://goo.gl/tpsmEJ#testing-patches
>