rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5808/1:b..l rcu: (detected by 0, t=10503 jiffies, g=11681, q=326 ncpus=2) task:syz.2.140 state:R running task stack:21424 pid:5808 tgid:5808 ppid:5228 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:216 Code: 00 d7 03 00 65 8b 15 90 4c 70 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9001705efc0 EFLAGS: 00000246 RAX: ffffffff81ca61d0 RBX: 0000000000000000 RCX: ffff888019f20000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffff88801e6c3800 R08: ffffffff81ca610f R09: 1ffffffff1fed855 R10: dffffc0000000000 R11: fffffbfff1fed856 R12: ffffc9001705f0c0 R13: 1ffff92002e0be18 R14: ffffea0001437b00 R15: ffff888068c982c0 xas_reload+0x290/0x470 include/linux/xarray.h:1606 find_get_entry mm/filemap.c:2007 [inline] find_lock_entries+0x306/0x10f0 mm/filemap.c:2091 shmem_undo_range+0x2d6/0x1df0 mm/shmem.c:1005 shmem_truncate_range mm/shmem.c:1132 [inline] shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1260 evict+0x532/0x950 fs/inode.c:704 __dentry_kill+0x20d/0x630 fs/dcache.c:610 dput+0x19f/0x2b0 fs/dcache.c:852 __fput+0x5f8/0x8a0 fs/file_table.c:430 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 get_signal+0x1695/0x1730 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x79/0x280 kernel/entry/common.c:231 exc_general_protection+0x410/0x5d0 arch/x86/kernel/traps.c:644 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7fc6f4b79e81 RSP: 002b:0000000020000090 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fc6f4d15f80 RCX: 00007fc6f4b79e79 RDX: 00000000200000c0 RSI: 0000000020000090 RDI: 0000000080202000 RBP: 00007fc6f4be7916 R08: 0000000020000140 R09: 0000000020000140 R10: 0000000020000100 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fc6f4d15f80 R15: 00007fff902f44e8 rcu: rcu_preempt kthread starved for 10545 jiffies! g11681 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:26640 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111