rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=8c5/1/0x4000000000000000 softirq=10501/10502 fqs=0 (t=10500 jiffies g=12965 q=226) rcu: rcu_preempt kthread starved for 10500 jiffies! g12965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28720 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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: 5516 Comm: syz-executor.1 Not tainted 5.16.0-next-20220117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:check_preemption_disabled+0x46/0x170 lib/smp_processor_id.c:19 Code: 8b 1d 3e 11 a9 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 <0f> 1f 44 00 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de 0f 1f 44 00 RSP: 0018:ffffc9000510fb58 EFLAGS: 00000046 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8a05fe60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff89ac2f80 R14: ffff88802fec3a80 R15: 0000000000000002 FS: 00007f8e9910a700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020800010 CR3: 00000000228a9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:433 [inline] lock_release+0x15a/0x720 kernel/locking/lockdep.c:5658 rcu_lock_release include/linux/rcupdate.h:273 [inline] rcu_read_unlock include/linux/rcupdate.h:727 [inline] aa_file_perm+0x590/0x1230 security/apparmor/file.c:625 common_file_perm security/apparmor/lsm.c:475 [inline] apparmor_file_permission+0x15e/0x4e0 security/apparmor/lsm.c:489 security_file_permission+0x4d/0xd0 security/security.c:1499 rw_verify_area+0xae/0x1c0 fs/read_write.c:385 vfs_write+0x177/0xae0 fs/read_write.c:581 ksys_pwrite64 fs/read_write.c:697 [inline] __do_sys_pwrite64 fs/read_write.c:707 [inline] __se_sys_pwrite64 fs/read_write.c:704 [inline] __x64_sys_pwrite64+0x1fd/0x250 fs/read_write.c:704 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: 0033:0x7f8e9a747fb7 Code: 08 89 3c 24 48 89 4c 24 18 e8 e5 f8 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 12 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 15 f9 ff ff 48 8b RSP: 002b:00007f8e99109f00 EFLAGS: 00000293 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f8e9a7de9c8 RCX: 00007f8e9a747fb7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0aaaaaaaaaaaab53 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000005 R14: 00000000208ac9f8 R15: 000000000005c855 NMI backtrace for cpu 0 CPU: 0 PID: 5520 Comm: syz-executor.5 Not tainted 5.16.0-next-20220117-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:111 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:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 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:1428 __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+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:syscall_exit_to_user_mode+0x0/0x60 kernel/entry/common.c:298 Code: 8b 3c 24 e8 a2 7d 03 f8 eb 12 66 90 0f 00 2d 87 aa 54 00 48 8b 3c 24 e9 2e f4 ff ff bf 01 00 00 00 e8 54 03 00 00 eb e2 66 90 <55> 48 89 fd e8 a7 c3 0c f8 9c 58 fa f6 c4 02 75 39 48 89 ef e8 87 RSP: 0018:ffffc9000517ff38 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88802b130000 RSI: ffffffff81d015cd RDI: ffffc9000517ff58 RBP: ffffc9000517ff48 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff81d088ba R11: 0000000000000000 R12: ffffc9000517ff58 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f8cccbf5fb7 Code: 08 89 3c 24 48 89 4c 24 18 e8 e5 f8 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 12 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 15 f9 ff ff 48 8b RSP: 002b:00007f8ccb5b7f00 EFLAGS: 00000293 ORIG_RAX: 0000000000000012 RAX: 0000000000000000 RBX: 00007f8cccc8c9c8 RCX: 00007f8cccbf5fb7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0aaaaaaaaaaaab53 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005 R13: 0000000000000005 R14: 0000000020942428 R15: 0000000000062c17 ---------------- Code disassembly (best guess): 0: 8b 1d 3e 11 a9 76 mov 0x76a9113e(%rip),%ebx # 0x76a91144 6: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx c: 31 ff xor %edi,%edi e: 89 de mov %ebx,%esi 10: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 15: 85 db test %ebx,%ebx 17: 74 11 je 0x2a 19: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1e: 44 89 e0 mov %r12d,%eax 21: 5b pop %rbx 22: 5d pop %rbp 23: 41 5c pop %r12 25: 41 5d pop %r13 27: 41 5e pop %r14 29: c3 retq * 2a: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) <-- trapping instruction 2f: 9c pushfq 30: 5b pop %rbx 31: 81 e3 00 02 00 00 and $0x200,%ebx 37: 31 ff xor %edi,%edi 39: 48 89 de mov %rbx,%rsi 3c: 0f .byte 0xf 3d: 1f (bad) 3e: 44 rex.R