rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=3de/1/0x4000000000000000 softirq=41464/41464 fqs=0 (detected by 1, t=10502 jiffies, g=69797, q=43) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19717 Comm: syz-executor.1 Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_acquire+0x27b/0xad0 kernel/locking/lockdep.c:5008 Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 f8 06 00 00 48 83 3d ea c8 5b 08 00 0f 84 a6 05 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 10 48 c7 RSP: 0018:ffffc90000007bb0 EFLAGS: 00000082 RAX: 1ffffffff136c6c1 RBX: ffff8880959cc280 RCX: ffffffff815a14fb RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000082 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c5f09e7 R10: fffffbfff18be13c R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8cc29d20 R14: 0000000000000000 R15: ffff8880959cc280 FS: 00007fafa50e7700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30525000 CR3: 0000000090248000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:636 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:480 [inline] enqueue_hrtimer+0x27/0x3f0 kernel/time/hrtimer.c:969 __run_hrtimer kernel/time/hrtimer.c:1541 [inline] __hrtimer_run_queues+0xc1e/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__sanitizer_cov_trace_pc+0x52/0x60 kernel/kcov.c:205 Code: 74 2b 8b 82 00 14 00 00 83 f8 02 75 20 48 8b 8a 08 14 00 00 8b 92 04 14 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 <48> 89 01 c3 66 2e 0f 1f 84 00 00 00 00 00 41 55 41 54 49 89 fc 55 RSP: 0018:ffffc90004b07078 EFLAGS: 00000216 RAX: 000000000000f4b2 RBX: ffffc90004b07105 RCX: ffffc90004889000 RDX: 0000000000040000 RSI: ffffffff83b40a4c RDI: 0000000000000001 RBP: ffff8880509e0d69 R08: 0000000000000002 R09: ffffc90004b07106 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000062 R13: 000000000000000c R14: dffffc0000000000 R15: ffffc90004b070f8 string_nocheck lib/vsprintf.c:616 [inline] symbol_string+0x21c/0x370 lib/vsprintf.c:976 pointer+0x185/0x970 lib/vsprintf.c:2223 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2621 seq_vprintf fs/seq_file.c:379 [inline] seq_printf+0x195/0x240 fs/seq_file.c:394 s_show+0xec/0x950 mm/vmalloc.c:3522 seq_read+0xac4/0x1070 fs/seq_file.c:248 pde_read fs/proc/inode.c:306 [inline] proc_reg_read+0x221/0x300 fs/proc/inode.c:318 do_loop_readv_writev fs/read_write.c:734 [inline] do_loop_readv_writev fs/read_write.c:721 [inline] do_iter_read+0x48e/0x6e0 fs/read_write.c:955 vfs_readv+0xe5/0x150 fs/read_write.c:1073 kernel_readv fs/splice.c:355 [inline] default_file_splice_read.constprop.0+0x4e6/0x9e0 fs/splice.c:412 do_splice_to+0x137/0x170 fs/splice.c:871 splice_direct_to_actor+0x307/0x980 fs/splice.c:950 do_splice_direct+0x1b3/0x280 fs/splice.c:1059 do_sendfile+0x55f/0xd40 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fafa50e6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000027880 RCX: 000000000045d4d9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000 R10: 000000010000004c R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffe739f107f R14: 00007fafa50e79c0 R15: 000000000118cf4c rcu: rcu_preempt kthread starved for 10502 jiffies! g69797 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:29664 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294