rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=74493, q=68) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295013214-4295002712), jiffies_till_next_fqs=1, root ->qsmask 0x0 syz-executor.0 R running task 26456 23849 10904 0x00004000 Call Trace: sched_show_task kernel/sched/core.c:5954 [inline] sched_show_task.cold+0x2ee/0x35d kernel/sched/core.c:5929 print_other_cpu_stall kernel/rcu/tree_stall.h:430 [inline] check_cpu_stall kernel/rcu/tree_stall.h:558 [inline] rcu_pending kernel/rcu/tree.c:3030 [inline] rcu_sched_clock_irq.cold+0xb23/0xc37 kernel/rcu/tree.c:2276 update_process_times+0x2d/0x70 kernel/time/timer.c:1726 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_stack_walk+0x81/0xf0 arch/x86/kernel/stacktrace.c:24 Code: 89 f6 e8 92 a2 07 00 8b 95 78 ff ff ff 85 d2 75 23 eb 35 31 d2 4c 89 e7 ff d3 84 c0 74 2a 48 8d bd 78 ff ff ff e8 1f a2 07 00 <8b> 85 78 ff ff ff 85 c0 74 14 48 8d bd 78 ff ff ff e8 49 90 07 00 RSP: 0018:ffffc90006eff358 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffffffff81641830 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 1ffff92000ddfe00 RDI: ffffc90006eff3a0 RBP: ffffc90006eff3e0 R08: 0000000000000001 R09: ffffc90006eff3b0 R10: ffffc90006eff380 R11: ffffc90006eff390 R12: ffffc90006eff410 R13: 0000000000000000 R14: ffff88809fbb6480 R15: ffff8880aa4001c0 stack_trace_save+0xac/0xe0 kernel/stacktrace.c:123 save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527 kmem_cache_alloc_trace+0x158/0x790 mm/slab.c:3551 kmalloc include/linux/slab.h:556 [inline] tty_alloc_file drivers/tty/tty_io.c:189 [inline] tty_open+0x14e/0xbb0 drivers/tty/tty_io.c:2029 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4e6/0x1380 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x12f3/0x3460 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x5eb/0x7e0 fs/open.c:1149 do_sys_open+0xf2/0x180 fs/open.c:1165 __do_sys_openat fs/open.c:1179 [inline] __se_sys_openat fs/open.c:1174 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1174 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb129b24c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb129b256d4 RCX: 000000000045b349 RDX: 0000000000004000 RSI: 0000000020000240 RDI: ffffffffffffff9c RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007ed R14: 00000000004c95a3 R15: 000000000075bf2c rcu: rcu_preempt kthread starved for 10502 jiffies! g74493 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29152 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline] rcu_gp_kthread+0xa10/0x1940 kernel/rcu/tree.c:1818 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 sched: RT throttling activated