rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7382/1:b..l (detected by 0, t=10502 jiffies, g=337457, q=541) task:syz-executor.5 state:R running task stack:23920 pid: 7382 ppid: 6602 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6459 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __raw_read_unlock include/linux/rwlock_api_smp.h:227 [inline] _raw_read_unlock+0x36/0x40 kernel/locking/spinlock.c:260 zap_pid_ns_processes+0x271/0x660 kernel/pid_namespace.c:207 find_child_reaper kernel/exit.c:542 [inline] forget_original_parent kernel/exit.c:631 [inline] exit_notify kernel/exit.c:668 [inline] do_exit+0x234c/0x2a30 kernel/exit.c:845 do_group_exit+0x125/0x310 kernel/exit.c:922 __do_sys_exit_group kernel/exit.c:933 [inline] __se_sys_exit_group kernel/exit.c:931 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931 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: 0033:0x7fc26d007ae9 RSP: 002b:00007fc26d64ec58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fc26d007ae9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 000000000000002e R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc26d061f8b R13: 000000000000000b R14: 0000000000000001 R15: 00007fc26d64ee40 rcu: rcu_preempt kthread timer wakeup didn't happen for 3950 jiffies! g337457 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=155746 rcu: rcu_preempt kthread starved for 3951 jiffies! g337457 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xb44/0x5960 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 29292 Comm: syz-executor.5 Not tainted 5.15.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:214 [inline] RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:895 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline] RIP: 0010:lock_acquire+0x3b3/0x510 kernel/locking/lockdep.c:5596 Code: 87 15 01 00 00 89 d2 be 08 00 00 00 48 89 d0 48 89 54 24 08 48 c1 f8 06 48 8d 3c c5 d0 87 6e 8d e8 52 ff 61 00 48 8b 54 24 08 <48> 0f a3 15 35 3e 12 0c 0f 83 0a fd ff ff 65 ff 05 58 a6 a5 7e 48 RSP: 0018:ffffc90000dc0c20 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff920001b8186 RCX: ffffffff815c498e RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8d6e87d0 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8d6e87d7 R10: fffffbfff1add0fa R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff903ed618 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555555e46708 CR3: 000000007ae89000 CR4: 00000000003526e0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:661 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x3e0 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xb02/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 d9 02 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 RSP: 0018:ffffc90018f877a8 EFLAGS: 00000293 RAX: 0000000080000001 RBX: ffffea0000d66ec0 RCX: 0000000000000000 RDX: ffff888165008000 RSI: ffffffff81ac74c7 RDI: 0000000000000003 RBP: ffffea0000d66ec0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81ac74b9 R11: 0000000000000000 R12: ffffea0000d66ec8 R13: 0000000000000000 R14: dffffc0000000000 R15: 00007fc26b695000 PagePoisoned include/linux/page-flags.h:218 [inline] PageSwapBacked include/linux/page-flags.h:371 [inline] mm_counter_file include/linux/mm.h:1959 [inline] mm_counter include/linux/mm.h:1968 [inline] zap_pte_range mm/memory.c:1361 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xdef/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x630 mm/mmap.c:3171 __mmput+0x122/0x4b0 kernel/fork.c:1115 mmput+0x58/0x60 kernel/fork.c:1136 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x21d0 kernel/signal.c:2855 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc26d007ae9 Code: Unable to access opcode bytes at RIP 0x7fc26d007abf. RSP: 002b:00007fc26a57d218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fc26d11af68 RCX: 00007fc26d007ae9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc26d11af68 RBP: 00007fc26d11af60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc26d11af6c R13: 00007fc26d64eb2f R14: 00007fc26a57d300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 87 15 01 00 00 89 xchg %edx,-0x76ffffff(%rip) # 0x89000007 6: d2 be 08 00 00 00 sarb %cl,0x8(%rsi) c: 48 89 d0 mov %rdx,%rax f: 48 89 54 24 08 mov %rdx,0x8(%rsp) 14: 48 c1 f8 06 sar $0x6,%rax 18: 48 8d 3c c5 d0 87 6e lea -0x72917830(,%rax,8),%rdi 1f: 8d 20: e8 52 ff 61 00 callq 0x61ff77 25: 48 8b 54 24 08 mov 0x8(%rsp),%rdx * 2a: 48 0f a3 15 35 3e 12 bt %rdx,0xc123e35(%rip) # 0xc123e67 <-- trapping instruction 31: 0c 32: 0f 83 0a fd ff ff jae 0xfffffd42 38: 65 ff 05 58 a6 a5 7e incl %gs:0x7ea5a658(%rip) # 0x7ea5a697 3f: 48 rex.W