* Re: BUG: unable to handle kernel paging request in delayed_put_task_struct
[not found] <f4f5e803e1a086d1cf055f705a68@google.com>
@ 2017-12-19 12:15 ` Dmitry Vyukov
2017-12-19 18:04 ` Paul E. McKenney
0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Vyukov @ 2017-12-19 12:15 UTC (permalink / raw)
To: syzbot
Cc: Andrew Morton, Davidlohr Bueso, LKML, Ingo Molnar, Paul McKenney,
Peter Zijlstra, rppt, Stephen Smalley, syzkaller-bugs, Al Viro
On Sun, Dec 3, 2017 at 3:24 PM, syzbot
<bot+50679d35ad280ab66b83cc309568910ba99dc9f6@syzkaller.appspotmail.com>
wrote:
> Hello,
>
> syzkaller hit the following crash on
> 5bef2980adef8a6032d4f4709aebe9486181052f
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
>
> Unfortunately, I don't have any reproducer for this bug yet.
>
>
> BUG: unable to handle kernel paging request at fffffffffffffff8
> IP: delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
> netlink: 6 bytes leftover after parsing attributes in process
> `syz-executor0'.
> PGD 5e28067 P4D 5e28067 PUD 5e2a067 PMD 0
> Oops: 0002 [#1] SMP KASAN
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in:
> CPU: 1 PID: 5363 Comm: syz-executor4 Not tainted 4.15.0-rc1-next-20171128+
> #54
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> task: ffff8801d8d244c0 task.stack: ffff8801c15d8000
> RIP: 0010:delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
> RSP: 0018:ffff8801db5078b0 EFLAGS: 00010206
> RAX: ffff8801d8d244c0 RBX: 1ffff1003b6a0f17 RCX: ffffffff81872631
> RDX: 0000000000000100 RSI: 000000003189bbb1 RDI: ffff8801d8bbb480
> RBP: ffff8801db507980 R08: 0000000000000005 R09: 0000000000000002
> R10: 0000000000000000 R11: ffffffff8748cd60 R12: ffff8801d8bbb5d0
> R13: ffff8801d8bbb5d8 R14: ffff8801d8bba1c0 R15: ffff8801db507c58
> FS: 00007f251e195700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: fffffffffffffff8 CR3: 00000001980c2000 CR4: 00000000001426e0
> Call Trace:
> <IRQ>
> __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
> rcu_do_batch kernel/rcu/tree.c:2674 [inline]
> invoke_rcu_callbacks kernel/rcu/tree.c:2933 [inline]
> __rcu_process_callbacks kernel/rcu/tree.c:2900 [inline]
> rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2917
> __do_softirq+0x29d/0xbb2 kernel/softirq.c:285
> invoke_softirq kernel/softirq.c:365 [inline]
> irq_exit+0x1d3/0x210 kernel/softirq.c:405
> exiting_irq arch/x86/include/asm/apic.h:540 [inline]
> smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
> apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:907
> </IRQ>
> RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:105 [inline]
> RIP: 0010:native_write_msr+0xa/0x30 arch/x86/include/asm/msr.h:148
> RSP: 0018:ffff8801c15de5a0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff11
> RAX: 00000000000000fb RBX: ffff8801db413124 RCX: 0000000000000830
> RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000830
> RBP: ffff8801c15de5a0 R08: 1ffff100382bbd00 R09: 0000000000000000
> R10: ffff8801c15de880 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff81270180
> paravirt_write_msr arch/x86/include/asm/paravirt.h:116 [inline]
> wrmsrl arch/x86/include/asm/paravirt.h:149 [inline]
> native_x2apic_icr_write arch/x86/include/asm/apic.h:240 [inline]
> __x2apic_send_IPI_dest+0x5c/0x80 arch/x86/kernel/apic/x2apic_phys.c:117
> x2apic_send_IPI+0x6f/0xa0 arch/x86/kernel/apic/x2apic_cluster.c:35
> native_send_call_func_single_ipi+0x55/0x70 arch/x86/kernel/smp.c:136
> arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:121 [inline]
> generic_exec_single+0x185/0x5b0 kernel/smp.c:179
> smp_call_function_single+0x2d2/0x560 kernel/smp.c:299
> smp_call_function_many+0x773/0x930 kernel/smp.c:434
> smp_call_function kernel/smp.c:492 [inline]
> on_each_cpu+0x3d/0x1b0 kernel/smp.c:602
> text_poke_bp+0xbb/0x170 arch/x86/kernel/alternative.c:807
> __jump_label_transform.isra.0+0x6a5/0x8a0 arch/x86/kernel/jump_label.c:102
> arch_jump_label_transform+0x2f/0x40 arch/x86/kernel/jump_label.c:110
> __jump_label_update+0x207/0x2d0 kernel/jump_label.c:368
> jump_label_update+0x22c/0x2b0 kernel/jump_label.c:735
> static_key_slow_dec_cpuslocked+0x176/0x1d0 kernel/jump_label.c:204
> __static_key_slow_dec kernel/jump_label.c:214 [inline]
> static_key_slow_dec+0x56/0x90 kernel/jump_label.c:228
> tracepoint_remove_func kernel/tracepoint.c:252 [inline]
> tracepoint_probe_unregister+0x70d/0x870 kernel/tracepoint.c:323
> trace_event_reg+0xed/0x320 kernel/trace/trace_events.c:309
> perf_trace_event_unreg.isra.2+0xad/0x1f0
> kernel/trace/trace_event_perf.c:155
> perf_trace_destroy+0xbc/0x100 kernel/trace/trace_event_perf.c:236
> tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:7940
> _free_event+0x3bd/0x10f0 kernel/events/core.c:4104
> put_event+0x24/0x30 kernel/events/core.c:4187
> perf_event_release_kernel+0x407/0xc10 kernel/events/core.c:4288
> perf_release+0x37/0x50 kernel/events/core.c:4298
> __fput+0x333/0x7f0 fs/file_table.c:210
> ____fput+0x15/0x20 fs/file_table.c:244
> task_work_run+0x199/0x270 kernel/task_work.c:113
> exit_task_work include/linux/task_work.h:22 [inline]
> do_exit+0x9bb/0x1ae0 kernel/exit.c:869
> do_group_exit+0x149/0x400 kernel/exit.c:972
> get_signal+0x73f/0x16c0 kernel/signal.c:2335
> do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809
> exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
> prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
> syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
> entry_SYSCALL_64_fastpath+0x94/0x96
> RIP: 0033:0x4529d9
> RSP: 002b:00007f251e194ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 0000000000758100 RCX: 00000000004529d9
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000758100
> RBP: 0000000000758100 R08: 000000000000055b R09: 00000000007580d8
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000a6f7ff R14: 00007f251e1959c0 R15: 0000000000000002
> Code: f1 f1 c7 40 04 00 f2 f2 f2 c7 40 08 f2 f2 f2 f2 c7 40 0c 00 f2 f2 f2
> c7 40 10 f3 f3 f3 f3 e8 01 7a 2e 00 4c 89 f7 e8 39 75 45 00 <cc> 78 00 00 00
> e8 ef 79 2e 00 e8 ea 79 2e 00 65 8b 05 73 80 bf
> RIP: delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178 RSP:
> ffff8801db5078b0
> CR2: fffffffffffffff8
> ---[ end trace d50259b7d3fcfc0a ]---
#syz dup: BUG: unable to handle kernel paging request in __switch_to
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@googlegroups.com.
> Please credit me with: Reported-by: syzbot <syzkaller@googlegroups.com>
>
> syzbot will keep track of this bug report.
> Once a fix for this bug is committed, please reply to this email with:
> #syz fix: exact-commit-title
> To mark this as a duplicate of another syzbot report, please reply with:
> #syz dup: exact-subject-of-another-report
> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug
> report.
> Note: all commands must start from beginning of the line in the email body.
>
> --
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> For more options, visit https://groups.google.com/d/optout.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: BUG: unable to handle kernel paging request in delayed_put_task_struct
2017-12-19 12:15 ` BUG: unable to handle kernel paging request in delayed_put_task_struct Dmitry Vyukov
@ 2017-12-19 18:04 ` Paul E. McKenney
2017-12-22 11:34 ` Dmitry Vyukov
0 siblings, 1 reply; 3+ messages in thread
From: Paul E. McKenney @ 2017-12-19 18:04 UTC (permalink / raw)
To: Dmitry Vyukov
Cc: syzbot, Andrew Morton, Davidlohr Bueso, LKML, Ingo Molnar,
Peter Zijlstra, rppt, Stephen Smalley, syzkaller-bugs, Al Viro
On Tue, Dec 19, 2017 at 01:15:26PM +0100, Dmitry Vyukov wrote:
> On Sun, Dec 3, 2017 at 3:24 PM, syzbot
> <bot+50679d35ad280ab66b83cc309568910ba99dc9f6@syzkaller.appspotmail.com>
> wrote:
> > Hello,
> >
> > syzkaller hit the following crash on
> > 5bef2980adef8a6032d4f4709aebe9486181052f
> > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> > compiler: gcc (GCC) 7.1.1 20170620
> > .config is attached
> > Raw console output is attached.
> >
> > Unfortunately, I don't have any reproducer for this bug yet.
That does make things more difficult. Nevertheless...
> > BUG: unable to handle kernel paging request at fffffffffffffff8
> > IP: delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
> > netlink: 6 bytes leftover after parsing attributes in process
> > `syz-executor0'.
> > PGD 5e28067 P4D 5e28067 PUD 5e2a067 PMD 0
> > Oops: 0002 [#1] SMP KASAN
> > Dumping ftrace buffer:
> > (ftrace buffer empty)
> > Modules linked in:
> > CPU: 1 PID: 5363 Comm: syz-executor4 Not tainted 4.15.0-rc1-next-20171128+
> > #54
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > task: ffff8801d8d244c0 task.stack: ffff8801c15d8000
> > RIP: 0010:delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
> > RSP: 0018:ffff8801db5078b0 EFLAGS: 00010206
> > RAX: ffff8801d8d244c0 RBX: 1ffff1003b6a0f17 RCX: ffffffff81872631
> > RDX: 0000000000000100 RSI: 000000003189bbb1 RDI: ffff8801d8bbb480
> > RBP: ffff8801db507980 R08: 0000000000000005 R09: 0000000000000002
> > R10: 0000000000000000 R11: ffffffff8748cd60 R12: ffff8801d8bbb5d0
> > R13: ffff8801d8bbb5d8 R14: ffff8801d8bba1c0 R15: ffff8801db507c58
> > FS: 00007f251e195700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: fffffffffffffff8 CR3: 00000001980c2000 CR4: 00000000001426e0
> > Call Trace:
> > <IRQ>
> > __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
If you do find a reproducer, please try reproducing with
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y, which checks for the call_rcu()
equivalent to double frees.
Thanx, Paul
> > rcu_do_batch kernel/rcu/tree.c:2674 [inline]
> > invoke_rcu_callbacks kernel/rcu/tree.c:2933 [inline]
> > __rcu_process_callbacks kernel/rcu/tree.c:2900 [inline]
> > rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2917
> > __do_softirq+0x29d/0xbb2 kernel/softirq.c:285
> > invoke_softirq kernel/softirq.c:365 [inline]
> > irq_exit+0x1d3/0x210 kernel/softirq.c:405
> > exiting_irq arch/x86/include/asm/apic.h:540 [inline]
> > smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
> > apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:907
> > </IRQ>
> > RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:105 [inline]
> > RIP: 0010:native_write_msr+0xa/0x30 arch/x86/include/asm/msr.h:148
> > RSP: 0018:ffff8801c15de5a0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff11
> > RAX: 00000000000000fb RBX: ffff8801db413124 RCX: 0000000000000830
> > RDX: 0000000000000000 RSI: 00000000000000fb RDI: 0000000000000830
> > RBP: ffff8801c15de5a0 R08: 1ffff100382bbd00 R09: 0000000000000000
> > R10: ffff8801c15de880 R11: 0000000000000000 R12: 0000000000000000
> > R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff81270180
> > paravirt_write_msr arch/x86/include/asm/paravirt.h:116 [inline]
> > wrmsrl arch/x86/include/asm/paravirt.h:149 [inline]
> > native_x2apic_icr_write arch/x86/include/asm/apic.h:240 [inline]
> > __x2apic_send_IPI_dest+0x5c/0x80 arch/x86/kernel/apic/x2apic_phys.c:117
> > x2apic_send_IPI+0x6f/0xa0 arch/x86/kernel/apic/x2apic_cluster.c:35
> > native_send_call_func_single_ipi+0x55/0x70 arch/x86/kernel/smp.c:136
> > arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:121 [inline]
> > generic_exec_single+0x185/0x5b0 kernel/smp.c:179
> > smp_call_function_single+0x2d2/0x560 kernel/smp.c:299
> > smp_call_function_many+0x773/0x930 kernel/smp.c:434
> > smp_call_function kernel/smp.c:492 [inline]
> > on_each_cpu+0x3d/0x1b0 kernel/smp.c:602
> > text_poke_bp+0xbb/0x170 arch/x86/kernel/alternative.c:807
> > __jump_label_transform.isra.0+0x6a5/0x8a0 arch/x86/kernel/jump_label.c:102
> > arch_jump_label_transform+0x2f/0x40 arch/x86/kernel/jump_label.c:110
> > __jump_label_update+0x207/0x2d0 kernel/jump_label.c:368
> > jump_label_update+0x22c/0x2b0 kernel/jump_label.c:735
> > static_key_slow_dec_cpuslocked+0x176/0x1d0 kernel/jump_label.c:204
> > __static_key_slow_dec kernel/jump_label.c:214 [inline]
> > static_key_slow_dec+0x56/0x90 kernel/jump_label.c:228
> > tracepoint_remove_func kernel/tracepoint.c:252 [inline]
> > tracepoint_probe_unregister+0x70d/0x870 kernel/tracepoint.c:323
> > trace_event_reg+0xed/0x320 kernel/trace/trace_events.c:309
> > perf_trace_event_unreg.isra.2+0xad/0x1f0
> > kernel/trace/trace_event_perf.c:155
> > perf_trace_destroy+0xbc/0x100 kernel/trace/trace_event_perf.c:236
> > tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:7940
> > _free_event+0x3bd/0x10f0 kernel/events/core.c:4104
> > put_event+0x24/0x30 kernel/events/core.c:4187
> > perf_event_release_kernel+0x407/0xc10 kernel/events/core.c:4288
> > perf_release+0x37/0x50 kernel/events/core.c:4298
> > __fput+0x333/0x7f0 fs/file_table.c:210
> > ____fput+0x15/0x20 fs/file_table.c:244
> > task_work_run+0x199/0x270 kernel/task_work.c:113
> > exit_task_work include/linux/task_work.h:22 [inline]
> > do_exit+0x9bb/0x1ae0 kernel/exit.c:869
> > do_group_exit+0x149/0x400 kernel/exit.c:972
> > get_signal+0x73f/0x16c0 kernel/signal.c:2335
> > do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809
> > exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
> > prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
> > syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
> > entry_SYSCALL_64_fastpath+0x94/0x96
> > RIP: 0033:0x4529d9
> > RSP: 002b:00007f251e194ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> > RAX: fffffffffffffe00 RBX: 0000000000758100 RCX: 00000000004529d9
> > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000758100
> > RBP: 0000000000758100 R08: 000000000000055b R09: 00000000007580d8
> > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> > R13: 0000000000a6f7ff R14: 00007f251e1959c0 R15: 0000000000000002
> > Code: f1 f1 c7 40 04 00 f2 f2 f2 c7 40 08 f2 f2 f2 f2 c7 40 0c 00 f2 f2 f2
> > c7 40 10 f3 f3 f3 f3 e8 01 7a 2e 00 4c 89 f7 e8 39 75 45 00 <cc> 78 00 00 00
> > e8 ef 79 2e 00 e8 ea 79 2e 00 65 8b 05 73 80 bf
> > RIP: delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178 RSP:
> > ffff8801db5078b0
> > CR2: fffffffffffffff8
> > ---[ end trace d50259b7d3fcfc0a ]---
>
> #syz dup: BUG: unable to handle kernel paging request in __switch_to
>
> > ---
> > This bug is generated by a dumb bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for details.
> > Direct all questions to syzkaller@googlegroups.com.
> > Please credit me with: Reported-by: syzbot <syzkaller@googlegroups.com>
> >
> > syzbot will keep track of this bug report.
> > Once a fix for this bug is committed, please reply to this email with:
> > #syz fix: exact-commit-title
> > To mark this as a duplicate of another syzbot report, please reply with:
> > #syz dup: exact-subject-of-another-report
> > If it's a one-off invalid bug report, please reply with:
> > #syz invalid
> > Note: if the crash happens again, it will cause creation of a new bug
> > report.
> > Note: all commands must start from beginning of the line in the email body.
> >
> > --
> > You received this message because you are subscribed to the Google Groups
> > "syzkaller-bugs" group.
> > To unsubscribe from this group and stop receiving emails from it, send an
> > email to syzkaller-bugs+unsubscribe@googlegroups.com.
> > To view this discussion on the web visit
> > https://groups.google.com/d/msgid/syzkaller-bugs/f4f5e803e1a086d1cf055f705a68%40google.com.
> > For more options, visit https://groups.google.com/d/optout.
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: BUG: unable to handle kernel paging request in delayed_put_task_struct
2017-12-19 18:04 ` Paul E. McKenney
@ 2017-12-22 11:34 ` Dmitry Vyukov
0 siblings, 0 replies; 3+ messages in thread
From: Dmitry Vyukov @ 2017-12-22 11:34 UTC (permalink / raw)
To: Paul McKenney
Cc: syzbot, Andrew Morton, Davidlohr Bueso, LKML, Ingo Molnar,
Peter Zijlstra, rppt, Stephen Smalley, syzkaller-bugs, Al Viro
On Tue, Dec 19, 2017 at 7:04 PM, Paul E. McKenney
<paulmck@linux.vnet.ibm.com> wrote:
> On Tue, Dec 19, 2017 at 01:15:26PM +0100, Dmitry Vyukov wrote:
>> On Sun, Dec 3, 2017 at 3:24 PM, syzbot
>> <bot+50679d35ad280ab66b83cc309568910ba99dc9f6@syzkaller.appspotmail.com>
>> wrote:
>> > Hello,
>> >
>> > syzkaller hit the following crash on
>> > 5bef2980adef8a6032d4f4709aebe9486181052f
>> > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
>> > compiler: gcc (GCC) 7.1.1 20170620
>> > .config is attached
>> > Raw console output is attached.
>> >
>> > Unfortunately, I don't have any reproducer for this bug yet.
>
> That does make things more difficult. Nevertheless...
>
>> > BUG: unable to handle kernel paging request at fffffffffffffff8
>> > IP: delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
>> > netlink: 6 bytes leftover after parsing attributes in process
>> > `syz-executor0'.
>> > PGD 5e28067 P4D 5e28067 PUD 5e2a067 PMD 0
>> > Oops: 0002 [#1] SMP KASAN
>> > Dumping ftrace buffer:
>> > (ftrace buffer empty)
>> > Modules linked in:
>> > CPU: 1 PID: 5363 Comm: syz-executor4 Not tainted 4.15.0-rc1-next-20171128+
>> > #54
>> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>> > Google 01/01/2011
>> > task: ffff8801d8d244c0 task.stack: ffff8801c15d8000
>> > RIP: 0010:delayed_put_task_struct+0x87/0x3d0 kernel/exit.c:178
>> > RSP: 0018:ffff8801db5078b0 EFLAGS: 00010206
>> > RAX: ffff8801d8d244c0 RBX: 1ffff1003b6a0f17 RCX: ffffffff81872631
>> > RDX: 0000000000000100 RSI: 000000003189bbb1 RDI: ffff8801d8bbb480
>> > RBP: ffff8801db507980 R08: 0000000000000005 R09: 0000000000000002
>> > R10: 0000000000000000 R11: ffffffff8748cd60 R12: ffff8801d8bbb5d0
>> > R13: ffff8801d8bbb5d8 R14: ffff8801d8bba1c0 R15: ffff8801db507c58
>> > FS: 00007f251e195700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000
>> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> > CR2: fffffffffffffff8 CR3: 00000001980c2000 CR4: 00000000001426e0
>> > Call Trace:
>> > <IRQ>
>> > __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
>
> If you do find a reproducer, please try reproducing with
> CONFIG_DEBUG_OBJECTS_RCU_HEAD=y, which checks for the call_rcu()
> equivalent to double frees.
This looks like a generally useful config for debugging, so I just
enabled CONFIG_DEBUG_OBJECTS* in all runs.
But this particular bug was already root caused. You can see that it's
marked as a duplicate of "BUG: unable to handle kernel paging request
in __switch_to" in the previous email.
All syzbot reported bugs are here:
https://groups.google.com/forum/#!forum/syzkaller-bugs
You can find "BUG: unable to handle kernel paging request in
__switch_to" there and see what was the resolution.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-12-19 12:15 ` BUG: unable to handle kernel paging request in delayed_put_task_struct Dmitry Vyukov
2017-12-19 18:04 ` Paul E. McKenney
2017-12-22 11:34 ` Dmitry Vyukov
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