* 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. > > -- > 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 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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