rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=f35/1/0x4000000000000000 softirq=303814/303815 fqs=5090 (t=10502 jiffies g=520497 q=2134) NMI backtrace for cpu 0 CPU: 0 PID: 19828 Comm: kworker/u4:14 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound io_ring_exit_work 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:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 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:1421 __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:__orc_find+0x3f/0xf0 arch/x86/kernel/unwind_orc.c:53 Code: 85 d2 0f 84 95 00 00 00 4c 39 e7 49 89 fd 0f 87 9a 00 00 00 49 bf 00 00 00 00 00 fc ff df 49 89 fe 48 89 fd eb 0c 48 8d 6b 04 <49> 89 de 49 39 ec 72 4d 4c 89 e0 48 29 e8 48 89 c2 48 c1 e8 3f 48 RSP: 0018:ffffc9000b0275f8 EFLAGS: 00000212 RAX: ffffffff81be20be RBX: ffffffff8d8407b4 RCX: ffffffff81be20fb RDX: 0000000000000000 RSI: ffffffff8df5d1e8 RDI: ffffffff8d84078c RBP: ffffffff8d8407b8 R08: 0000000000000000 R09: ffffffff8df5d1e8 R10: fffff52001604eee R11: 0000000000086089 R12: ffffffff8d8407e0 R13: ffffffff8d84078c R14: ffffffff8d84078c R15: dffffc0000000000 orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x32a/0x1ce0 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1700 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1726 slab_free mm/slub.c:3492 [inline] kfree+0xf3/0x550 mm/slub.c:4552 __io_remove_buffers.part.0+0x115/0x220 fs/io_uring.c:4327 __io_remove_buffers fs/io_uring.c:9263 [inline] io_destroy_buffers fs/io_uring.c:9263 [inline] io_ring_ctx_free fs/io_uring.c:9319 [inline] io_ring_exit_work+0x74d/0xbe8 fs/io_uring.c:9495 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 85 d2 test %edx,%edx 2: 0f 84 95 00 00 00 je 0x9d 8: 4c 39 e7 cmp %r12,%rdi b: 49 89 fd mov %rdi,%r13 e: 0f 87 9a 00 00 00 ja 0xae 14: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 1b: fc ff df 1e: 49 89 fe mov %rdi,%r14 21: 48 89 fd mov %rdi,%rbp 24: eb 0c jmp 0x32 26: 48 8d 6b 04 lea 0x4(%rbx),%rbp * 2a: 49 89 de mov %rbx,%r14 <-- trapping instruction 2d: 49 39 ec cmp %rbp,%r12 30: 72 4d jb 0x7f 32: 4c 89 e0 mov %r12,%rax 35: 48 29 e8 sub %rbp,%rax 38: 48 89 c2 mov %rax,%rdx 3b: 48 c1 e8 3f shr $0x3f,%rax 3f: 48 rex.W