rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=415/1/0x4000000000000000 softirq=241948/241971 fqs=481 (t=10502 jiffies g=477365 q=1963) rcu: rcu_preempt kthread starved for 9344 jiffies! g477365 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28472 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1 Comm: systemd Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:30 [inline] RIP: 0010:__orc_find+0x6f/0xf0 arch/x86/kernel/unwind_orc.c:52 Code: 72 4d 4c 89 e0 48 29 e8 48 89 c2 48 c1 e8 3f 48 c1 fa 02 48 01 d0 48 d1 f8 48 8d 5c 85 00 48 89 d8 48 c1 e8 03 42 0f b6 14 38 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 48 63 03 48 01 RSP: 0018:ffffc90000e7f550 EFLAGS: 00000a07 RAX: 1ffffffff1b066a6 RBX: ffffffff8d833534 RCX: ffffffff81cb4a39 RDX: 0000000000000000 RSI: ffffffff8df51a44 RDI: ffffffff8d833534 RBP: ffffffff8d833534 R08: 0000000000000000 R09: ffffffff8df51a44 R10: fffff520001cfed9 R11: 0000000000086089 R12: ffffffff8d833534 R13: ffffffff8d833534 R14: ffffffff8d833534 R15: dffffc0000000000 FS: 00007f97580bd500(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c02d5a8df8 CR3: 0000000028bf7000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x32a/0x1ce0 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa1/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x1e4/0x480 mm/slab.c:3575 kmalloc include/linux/slab.h:591 [inline] single_open+0x49/0x1e0 fs/seq_file.c:591 do_dentry_open+0x4c8/0x11d0 fs/open.c:822 do_open fs/namei.c:3428 [inline] path_openat+0x1c9a/0x2740 fs/namei.c:3561 do_filp_open+0x1aa/0x400 fs/namei.c:3588 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200 do_sys_open fs/open.c:1216 [inline] __do_sys_open fs/open.c:1224 [inline] __se_sys_open fs/open.c:1220 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1220 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: 0033:0x7f975668670d Code: 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 47 9e 01 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffca043fe90 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000056409a8a8bf0 RCX: 00007f975668670d RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffca043ff50 RBP: 0000000000000008 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000080000 R11: 0000000000000293 R12: 00007f9757dc07b4 R13: 0000000000000001 R14: 00007ffca043ff50 R15: 0000000000000000 NMI backtrace for cpu 1 CPU: 1 PID: 15714 Comm: syz-executor.2 Not tainted 5.15.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 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:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:trace_timer_expire_entry include/trace/events/timer.h:90 [inline] RIP: 0010:call_timer_fn+0x12b/0x6b0 kernel/time/timer.c:1420 Code: 89 44 24 58 e8 c6 cd 10 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 6c 24 38 31 d2 68 d5 76 64 81 31 f6 48 89 ef e8 c5 20 f6 ff <58> 0f 1f 44 00 00 e8 9a cd 10 00 e8 95 cd 10 00 65 44 8b 3d 25 1e RSP: 0018:ffffc90000fd8d30 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000101 RCX: ffffffff815a469f RDX: 1ffff110063ccd66 RSI: 0000000000000101 RDI: 0000000000000000 RBP: ffffc90000fd8d70 R08: 0000000000000000 R09: ffffffff8fcffa07 R10: fffffbfff1f9ff40 R11: 0000000000000000 R12: ffff888086f20810 R13: 1ffff920001fb1a8 R14: ffffffff873b7600 R15: ffff8880b9d20240 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 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 29 ab 8c 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:ffffc90019cb77a8 EFLAGS: 00000286 RAX: 0000000080000001 RBX: 0000000000000000 RCX: ffff888031e66140 RDX: 0000000000000000 RSI: ffff888031e66140 RDI: 0000000000000003 RBP: ffffea0001bb3940 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff819e5752 R11: 0000000000000000 R12: ffffea0001bb3948 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000475000 zap_pte_range mm/memory.c:1359 [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+0xd45/0x2a10 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/0x2160 kernel/signal.c:2868 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:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4196e4 Code: Unable to access opcode bytes at RIP 0x4196ba. RSP: 002b:00007f002878acc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: 0000000000000006 RBX: 6666666666666667 RCX: 00000000004196e4 RDX: 0000000000000002 RSI: 00007f002878ad60 RDI: 00000000ffffff9c RBP: 00007f002878ad60 R08: 0000000000000000 R09: 00237265646e6962 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007fff560cb15f R14: 00007f002878b300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 72 4d jb 0x4f 2: 4c 89 e0 mov %r12,%rax 5: 48 29 e8 sub %rbp,%rax 8: 48 89 c2 mov %rax,%rdx b: 48 c1 e8 3f shr $0x3f,%rax f: 48 c1 fa 02 sar $0x2,%rdx 13: 48 01 d0 add %rdx,%rax 16: 48 d1 f8 sar %rax 19: 48 8d 5c 85 00 lea 0x0(%rbp,%rax,4),%rbx 1e: 48 89 d8 mov %rbx,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 42 0f b6 14 38 movzbl (%rax,%r15,1),%edx * 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 04 jl 0x3b 37: 84 d2 test %dl,%dl 39: 75 48 jne 0x83 3b: 48 63 03 movslq (%rbx),%rax 3e: 48 rex.W 3f: 01 .byte 0x1