syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=53a/1/0x4000000000000000 softirq=138276/138276 fqs=0 
	(t=10500 jiffies g=252669 q=20)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g252669 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=89275
rcu: rcu_preempt kthread starved for 10500 jiffies! g252669 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:29096 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5940
 schedule+0xd3/0x270 kernel/sched/core.c:6019
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1879
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 19123 Comm: syz-executor.1 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
RIP: 0010:rcu_is_watching+0x7f/0xc0 kernel/rcu/tree.c:1161
Code: 01 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1f 8b 83 48 01 00 00 d1 e8 83 e0 01 <65> ff 0d 1a 64 a1 7e 74 03 5b 5d c3 e8 8f b9 9f ff 5b 5d c3 e8 b8
RSP: 0018:ffffc90000007dd8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffff8880b9c52a00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000010003 RDI: ffff8880b9c52b48
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff81646acc R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: ffff8880b9c423c0 R15: 0000000000000001
FS:  00007ff9e2277700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005461f8 CR3: 00000000172af000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
 rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123
 trace_hrtimer_start include/trace/events/timer.h:195 [inline]
 debug_activate kernel/time/hrtimer.c:476 [inline]
 enqueue_hrtimer+0x2bd/0x3e0 kernel/time/hrtimer.c:982
 __run_hrtimer kernel/time/hrtimer.c:1554 [inline]
 __hrtimer_run_queues+0xb02/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:check_kcov_mode+0x31/0x40 kernel/kcov.c:175
Code: 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 34 15 00 00 85 d2 74 0b 8b 86 10 15 00 00 39 f8 0f 94 c0 <c3> 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 65 8b 15 f7 36
RSP: 0018:ffffc9000282f7f0 EFLAGS: 00000297
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88808671e2c0 RDI: 0000000000000003
RBP: ffff888024718948 R08: 0000000000000000 R09: ffff8880139b8d23
R10: ffffffff81a79a08 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880139b8d20
 write_comp_data kernel/kcov.c:218 [inline]
 __sanitizer_cov_trace_const_cmp8+0x1d/0x70 kernel/kcov.c:291
 follow_page_pte+0x228/0xc50 mm/gup.c:620
 follow_pmd_mask mm/gup.c:720 [inline]
 follow_pud_mask mm/gup.c:765 [inline]
 follow_p4d_mask mm/gup.c:791 [inline]
 follow_page_mask+0xb9e/0x1520 mm/gup.c:850
 __get_user_pages+0x734/0x1430 mm/gup.c:1171
 __get_user_pages_locked mm/gup.c:1359 [inline]
 __get_user_pages_remote+0x18f/0x840 mm/gup.c:1865
 pin_user_pages_remote+0x63/0x90 mm/gup.c:2938
 process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
 process_vm_rw_core.constprop.0+0x445/0x990 mm/process_vm_access.c:215
 process_vm_rw+0x29c/0x300 mm/process_vm_access.c:283
 __do_sys_process_vm_writev mm/process_vm_access.c:303 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:298 [inline]
 __x64_sys_process_vm_writev+0xdf/0x1b0 mm/process_vm_access.c:298
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff9e2277188 EFLAGS: 00000246 ORIG_RAX: 0000000000000137
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000079 RSI: 0000000020000000 RDI: 0000000000000178
RBP: 00000000004bfcc4 R08: 0000000000000008 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffda7db9faf R14: 00007ff9e2277300 R15: 0000000000022000
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 19123 Comm: syz-executor.1 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1207 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x21/0x150 kernel/rcu/tree.c:1199
Code: e9 4b fe ff ff 0f 1f 40 00 65 8b 15 49 42 a1 7e 81 e2 00 00 f0 00 b8 01 00 00 00 75 0a 8b 15 76 88 0b 0c 85 d2 75 01 c3 55 53 <65> ff 05 28 42 a1 7e e8 43 82 c9 07 48 c7 c3 00 2a 05 00 83 f8 07
RSP: 0018:ffffc90000007c40 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff815a3941
RDX: 0000000000000001 RSI: 0000000000010004 RDI: ffff8880b9c52b48
RBP: 1ffff92000000f8f R08: 0000000000000000 R09: ffffffff8d6c3517
R10: fffffbfff1ad86a2 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff898db720 R14: 1ffff92000000fab R15: ffff888031e2bb40
FS:  00007ff9e2277700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005461f8 CR3: 00000000172af000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
 rcu_read_lock_held_common kernel/rcu/update.c:102 [inline]
 rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x522/0x720 kernel/locking/lockdep.c:5636
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:191
 debug_object_deactivate lib/debugobjects.c:752 [inline]
 debug_object_deactivate+0x264/0x300 lib/debugobjects.c:718
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1505 [inline]
 __hrtimer_run_queues+0x3f8/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:check_kcov_mode+0x31/0x40 kernel/kcov.c:175
Code: 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 34 15 00 00 85 d2 74 0b 8b 86 10 15 00 00 39 f8 0f 94 c0 <c3> 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 31 c0 65 8b 15 f7 36
RSP: 0018:ffffc9000282f7f0 EFLAGS: 00000297
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88808671e2c0 RDI: 0000000000000003
RBP: ffff888024718948 R08: 0000000000000000 R09: ffff8880139b8d23
R10: ffffffff81a79a08 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880139b8d20
 write_comp_data kernel/kcov.c:218 [inline]
 __sanitizer_cov_trace_const_cmp8+0x1d/0x70 kernel/kcov.c:291
 follow_page_pte+0x228/0xc50 mm/gup.c:620
 follow_pmd_mask mm/gup.c:720 [inline]
 follow_pud_mask mm/gup.c:765 [inline]
 follow_p4d_mask mm/gup.c:791 [inline]
 follow_page_mask+0xb9e/0x1520 mm/gup.c:850
 __get_user_pages+0x734/0x1430 mm/gup.c:1171
 __get_user_pages_locked mm/gup.c:1359 [inline]
 __get_user_pages_remote+0x18f/0x840 mm/gup.c:1865
 pin_user_pages_remote+0x63/0x90 mm/gup.c:2938
 process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
 process_vm_rw_core.constprop.0+0x445/0x990 mm/process_vm_access.c:215
 process_vm_rw+0x29c/0x300 mm/process_vm_access.c:283
 __do_sys_process_vm_writev mm/process_vm_access.c:303 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:298 [inline]
 __x64_sys_process_vm_writev+0xdf/0x1b0 mm/process_vm_access.c:298
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff9e2277188 EFLAGS: 00000246 ORIG_RAX: 0000000000000137
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000079 RSI: 0000000020000000 RDI: 0000000000000178
RBP: 00000000004bfcc4 R08: 0000000000000008 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffda7db9faf R14: 00007ff9e2277300 R15: 0000000000022000
NMI backtrace for cpu 1
CPU: 1 PID: 19158 Comm: syz-executor.4 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:342
 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:700 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq.cold+0x9f/0x747 kernel/rcu/tree.c:2641
 update_process_times+0x16d/0x200 kernel/time/timer.c:1783
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:967
Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 50 48 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31
RSP: 0018:ffffc90002ecfcb0 EFLAGS: 00000246
RAX: 0000000000040000 RBX: ffff8880b9c55de0 RCX: ffffc90002861000
RDX: 0000000000040000 RSI: ffffffff81697880 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff816978a6 R11: 0000000000000000 R12: ffffed101738abbd
R13: 0000000000000000 R14: ffff8880b9c55de8 R15: 0000000000000001
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1133
 on_each_cpu include/linux/smp.h:71 [inline]
 clock_was_set+0x21/0x30 kernel/time/hrtimer.c:889
 do_settimeofday64 kernel/time/timekeeping.c:1327 [inline]
 do_settimeofday64+0x3dd/0x5c0 kernel/time/timekeeping.c:1293
 do_sys_settimeofday64 kernel/time/time.c:195 [inline]
 do_sys_settimeofday64+0x1de/0x260 kernel/time/time.c:169
 __do_sys_clock_settime kernel/time/posix-timers.c:1079 [inline]
 __se_sys_clock_settime kernel/time/posix-timers.c:1067 [inline]
 __x64_sys_clock_settime+0x1a1/0x280 kernel/time/posix-timers.c:1067
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f895f9a6188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000000
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffee0fe817f R14: 00007f895f9a6300 R15: 0000000000022000