rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=183869, q=272) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295089451-4295078949), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.3 R running task 27168 1261 8124 0x00000000 Call Trace: sched_show_task.cold+0x332/0x396 kernel/sched/core.c:5337 print_other_cpu_stall kernel/rcu/tree.c:1430 [inline] check_cpu_stall kernel/rcu/tree.c:1557 [inline] __rcu_pending kernel/rcu/tree.c:3293 [inline] rcu_pending kernel/rcu/tree.c:3336 [inline] rcu_check_callbacks.cold+0xb37/0xe19 kernel/rcu/tree.c:2682 update_process_times+0x2a/0x70 kernel/time/timer.c:1650 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:168 tick_sched_timer+0xfc/0x290 kernel/time/tick-sched.c:1278 __run_hrtimer kernel/time/hrtimer.c:1465 [inline] __hrtimer_run_queues+0x3f6/0xe60 kernel/time/hrtimer.c:1527 hrtimer_interrupt+0x326/0x9e0 kernel/time/hrtimer.c:1585 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1071 [inline] smp_apic_timer_interrupt+0x10c/0x550 arch/x86/kernel/apic/apic.c:1096 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:unwind_next_frame+0xacb/0x1400 arch/x86/kernel/unwind_orc.c:548 Code: 41 c6 46 35 00 48 8b 4c 24 20 4c 89 c0 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 0f b6 04 10 48 89 ce 48 c1 ee 03 0f b6 14 16 <4c> 89 c6 83 e6 07 40 38 f0 40 0f 9e c6 84 c0 0f 95 c0 40 84 c6 0f RSP: 0018:ffff888049b7f4b8 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 1ffff1100936fea0 RCX: ffffffff8b99d101 RDX: 0000000000000000 RSI: 1ffffffff1733a20 RDI: ffff888049b7f640 RBP: 0000000000000001 R08: ffffffff8b99d100 R09: ffffffff8b99d0fc R10: ffff888049b7f647 R11: 0000000000074071 R12: ffff888049b7f910 R13: ffff888049b7f61d R14: ffff888049b7f5e8 R15: ffffffff8b99d0fc __save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc mm/slab.c:3397 [inline] kmem_cache_alloc_trace+0x11a/0x380 mm/slab.c:3623 kmalloc include/linux/slab.h:515 [inline] tty_alloc_file drivers/tty/tty_io.c:187 [inline] tty_open+0x138/0x990 drivers/tty/tty_io.c:2023 chrdev_open+0x266/0x770 fs/char_dev.c:423 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff7d089d669 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff7cf211168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff7d09bef80 RCX: 00007ff7d089d669 RDX: 0000000000000002 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 00007ff7d08f8560 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe7021ed2f R14: 00007ff7cf211300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10502 jiffies! g183869 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29160 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1818 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415