rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=38013, q=38) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294982385-4294971883), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g38013 f0x2 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:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 7433 Comm: syz-executor.1 Not tainted 5.16.0-rc5-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_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2597 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:unwind_next_frame+0x830/0x1ce0 arch/x86/kernel/unwind_orc.c:466 Code: 07 38 d0 7f 08 84 c0 0f 85 12 12 00 00 41 80 7e 34 00 0f 85 00 fc ff ff 80 3d 6d 77 48 0c 00 0f 85 f3 fb ff ff e9 c8 80 cc 07 <48> b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc90004677430 EFLAGS: 00000297 RAX: 0000000000000005 RBX: 1ffff920008cee8e RCX: ffffffff8e101ead RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8e101ea8 R09: 0000000000000001 R10: fffff520008ceeac R11: 000000000008808a R12: ffffc90004677550 R13: ffffc9000467753d R14: ffffc90004677508 R15: ffffffff8e101eac arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:269 [inline] kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3575 kmalloc include/linux/slab.h:590 [inline] tty_alloc_file drivers/tty/tty_io.c:187 [inline] tty_open+0x140/0x1000 drivers/tty/tty_io.c:2140 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x1250 fs/open.c:822 do_open fs/namei.c:3426 [inline] path_openat+0x1cad/0x2750 fs/namei.c:3559 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_openat fs/open.c:1244 [inline] __se_sys_openat fs/open.c:1239 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1239 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: 0033:0x7f168e283e99 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f168cbf9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f168e396f60 RCX: 00007f168e283e99 RDX: 0000000000000000 RSI: 0000000020000200 RDI: ffffffffffffff9c RBP: 00007f168e2de031 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc3a5d38f R14: 00007f168cbf9300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 38 d0 cmp %dl,%al 2: 7f 08 jg 0xc 4: 84 c0 test %al,%al 6: 0f 85 12 12 00 00 jne 0x121e c: 41 80 7e 34 00 cmpb $0x0,0x34(%r14) 11: 0f 85 00 fc ff ff jne 0xfffffc17 17: 80 3d 6d 77 48 0c 00 cmpb $0x0,0xc48776d(%rip) # 0xc48778b 1e: 0f 85 f3 fb ff ff jne 0xfffffc17 24: e9 c8 80 cc 07 jmpq 0x7cc80f1 * 29: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 30: fc ff df 33: 48 8b 54 24 08 mov 0x8(%rsp),%rdx 38: 48 c1 ea 03 shr $0x3,%rdx 3c: 80 .byte 0x80 3d: 3c 02 cmp $0x2,%al