rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=3c9/1/0x4000000000000000 softirq=137143/137143 fqs=29 (t=10500 jiffies g=263885 q=266) rcu: rcu_preempt kthread starved for 10428 jiffies! g263885 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:28952 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8842 Comm: syz-executor.0 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kasan_check_range+0x12b/0x180 mm/kasan/generic.c:190 Code: 3a 00 74 ef 49 8d 04 2c 48 85 d2 75 0b 48 89 da 48 29 c2 e9 55 ff ff ff 49 39 d2 75 17 49 0f be 02 41 83 e1 07 49 39 c1 7d 0a <5b> b8 01 00 00 00 5d 41 5c c3 44 89 c2 e8 93 ef ff ff 5b 83 f0 01 RSP: 0018:ffffc9000a697430 EFLAGS: 00000046 RAX: ffffed1027fff5b3 RBX: ffffed1027fff5b3 RCX: ffffffff81b3b6d6 RDX: ffffed1027fff5b3 RSI: 0000000000000008 RDI: ffff88813fffad90 RBP: ffffed1027fff5b2 R08: 0000000000000000 R09: ffff88813fffad97 R10: ffffed1027fff5b2 R11: 0000000000000000 R12: 00000000000024da R13: dffffc0000000000 R14: ffff88813fffa700 R15: 00000000000024d6 FS: 00007fbdd8ee1700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f40e004b4e5 CR3: 000000001e1cc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_long_read include/linux/atomic/atomic-instrumented.h:1183 [inline] zone_page_state include/linux/vmstat.h:210 [inline] __zone_watermark_unusable_free mm/page_alloc.c:3827 [inline] zone_watermark_fast mm/page_alloc.c:3926 [inline] get_page_from_freelist+0x1886/0x2f50 mm/page_alloc.c:4103 __alloc_pages_slowpath.constprop.0+0x95d/0x20d0 mm/page_alloc.c:4994 __alloc_pages+0x412/0x500 mm/page_alloc.c:5382 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x470 mm/slab.c:2593 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965 ____cache_alloc mm/slab.c:3048 [inline] ____cache_alloc mm/slab.c:3031 [inline] __do_cache_alloc mm/slab.c:3275 [inline] slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc_trace+0x380/0x4a0 mm/slab.c:3573 kmalloc include/linux/slab.h:590 [inline] io_add_buffers fs/io_uring.c:4405 [inline] io_provide_buffers fs/io_uring.c:4439 [inline] io_issue_sqe+0x2887/0x7010 fs/io_uring.c:6705 __io_queue_sqe fs/io_uring.c:6978 [inline] io_queue_sqe fs/io_uring.c:7020 [inline] io_submit_sqe fs/io_uring.c:7223 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7329 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10043 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: 0033:0x7fbddb98cae9 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:00007fbdd8ee1188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fbddbaa0020 RCX: 00007fbddb98cae9 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000004 RBP: 00007fbddb9e6f45 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe6ca12f5f R14: 00007fbdd8ee1300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 8840 Comm: syz-executor.0 Not tainted 5.15.0-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: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:prefetchw arch/x86/include/asm/processor.h:741 [inline] RIP: 0010:slab_alloc mm/slab.c:3319 [inline] RIP: 0010:kmem_cache_alloc_trace+0x193/0x4a0 mm/slab.c:3573 Code: 0f 84 3e 01 00 00 4d 85 ff 48 89 54 24 10 0f 85 d4 01 00 00 9c 58 f6 c4 02 0f 85 e3 01 00 00 4d 85 ff 74 01 fb 48 8b 74 24 10 <0f> 0d 0e 0f 1f 44 00 00 48 83 7b 50 00 0f 84 83 00 00 00 44 23 25 RSP: 0018:ffffc90009baf980 EFLAGS: 00000206 RAX: 0000000000000006 RBX: ffff888010c43400 RCX: 1ffffffff1fb8e26 RDX: 0000000000000000 RSI: ffff88818360e880 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff8fd4ab4f R10: 0000000000000001 R11: dffffc0000000000 R12: 0000000000400cc0 R13: 0000000000400cc0 R14: 0000000000000020 R15: 0000000000000200 kmalloc include/linux/slab.h:590 [inline] io_add_buffers fs/io_uring.c:4405 [inline] io_provide_buffers fs/io_uring.c:4439 [inline] io_issue_sqe+0x2887/0x7010 fs/io_uring.c:6705 __io_queue_sqe fs/io_uring.c:6978 [inline] io_queue_sqe fs/io_uring.c:7020 [inline] io_submit_sqe fs/io_uring.c:7223 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7329 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10043 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: 0033:0x7fbddb98cae9 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:00007fbdd8f02188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fbddba9ff60 RCX: 00007fbddb98cae9 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000004 RBP: 00007fbddb9e6f45 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe6ca12f5f R14: 00007fbdd8f02300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 3a 00 cmp (%rax),%al 2: 74 ef je 0xfffffff3 4: 49 8d 04 2c lea (%r12,%rbp,1),%rax 8: 48 85 d2 test %rdx,%rdx b: 75 0b jne 0x18 d: 48 89 da mov %rbx,%rdx 10: 48 29 c2 sub %rax,%rdx 13: e9 55 ff ff ff jmpq 0xffffff6d 18: 49 39 d2 cmp %rdx,%r10 1b: 75 17 jne 0x34 1d: 49 0f be 02 movsbq (%r10),%rax 21: 41 83 e1 07 and $0x7,%r9d 25: 49 39 c1 cmp %rax,%r9 28: 7d 0a jge 0x34 * 2a: 5b pop %rbx <-- trapping instruction 2b: b8 01 00 00 00 mov $0x1,%eax 30: 5d pop %rbp 31: 41 5c pop %r12 33: c3 retq 34: 44 89 c2 mov %r8d,%edx 37: e8 93 ef ff ff callq 0xffffefcf 3c: 5b pop %rbx 3d: 83 f0 01 xor $0x1,%eax