rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=127/1/0x4000000000000000 softirq=73393/73394 fqs=53 (t=10501 jiffies g=144049 q=237) rcu: rcu_preempt kthread starved for 10395 jiffies! g144049 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:28656 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: 30836 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:unwind_next_frame+0x49c/0x1ce0 arch/x86/kernel/unwind_orc.c:464 Code: ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 83 11 00 00 41 c7 06 00 00 00 00 31 c0 e9 f4 fb ff ff 48 ba 00 00 00 00 00 fc ff df <4c> 89 f9 48 c1 e9 03 0f b6 34 11 49 8d 4f 01 48 89 cf 48 c1 ef 03 RSP: 0018:ffffc90003757540 EFLAGS: 00000202 RAX: 0000000000000048 RBX: 1ffff920006eaeb0 RCX: ffffffff81e259e9 RDX: dffffc0000000000 RSI: ffffffff8dfa6294 RDI: ffffffff8d8740c8 RBP: 0000000000000001 R08: ffffffff8dfa6294 R09: 0000000000000001 R10: fffff520006eaece R11: 000000000008608a R12: ffffc90003757660 R13: ffffc9000375764d R14: ffffc90003757618 R15: ffffffff8dfa6298 FS: 00007fdf3354e700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdf3352d718 CR3: 00000000684a9000 CR4: 00000000003526e0 DR0: 00000000000043ce DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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] 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:6974 [inline] io_queue_sqe fs/io_uring.c:7016 [inline] io_submit_sqe fs/io_uring.c:7219 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7325 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10039 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: 0033:0x7fdf3601aae9 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:00007fdf3354e188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fdf3612e0e0 RCX: 00007fdf3601aae9 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000003 RBP: 00007fdf36074f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff44f15aef R14: 00007fdf3354e300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 30828 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:ffffc900035b7980 EFLAGS: 00000206 RAX: 0000000000000002 RBX: ffff888010c43400 RCX: 1ffffffff1fbb786 RDX: 0000000000000000 RSI: ffff8881819b1080 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffffff8fd60b47 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:6974 [inline] io_queue_sqe fs/io_uring.c:7016 [inline] io_submit_sqe fs/io_uring.c:7219 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7325 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10039 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: 0033:0x7fdf3601aae9 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:00007fdf33590188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fdf3612df60 RCX: 00007fdf3601aae9 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000003 RBP: 00007fdf36074f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff44f15aef R14: 00007fdf33590300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 03 0f add (%rdi),%ecx 2: b6 04 mov $0x4,%dh 4: 02 84 c0 74 08 3c 03 add 0x33c0874(%rax,%rax,8),%al b: 0f 8e 83 11 00 00 jle 0x1194 11: 41 c7 06 00 00 00 00 movl $0x0,(%r14) 18: 31 c0 xor %eax,%eax 1a: e9 f4 fb ff ff jmpq 0xfffffc13 1f: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 26: fc ff df * 29: 4c 89 f9 mov %r15,%rcx <-- trapping instruction 2c: 48 c1 e9 03 shr $0x3,%rcx 30: 0f b6 34 11 movzbl (%rcx,%rdx,1),%esi 34: 49 8d 4f 01 lea 0x1(%r15),%rcx 38: 48 89 cf mov %rcx,%rdi 3b: 48 c1 ef 03 shr $0x3,%rdi