rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=8e1/1/0x4000000000000000 softirq=209526/209526 fqs=21 (t=10502 jiffies g=409133 q=479) rcu: rcu_preempt kthread starved for 10460 jiffies! g409133 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:28352 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 kthread+0x3e5/0x4d0 kernel/kthread.c:319 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: 19 Comm: ksoftirqd/1 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count_sub+0x5f/0x150 kernel/sched/core.c:5439 Code: d6 0e 85 c9 75 1b 65 8b 05 3e 27 b3 7e 89 c2 81 e2 ff ff ff 7f 39 da 7c 13 81 fb fe 00 00 00 76 63 f7 db 65 01 1d 21 27 b3 7e <5b> c3 e8 3a ce 87 02 85 c0 74 f5 48 c7 c0 28 51 6e 8d 48 ba 00 00 RSP: 0018:ffffc90000faf288 EFLAGS: 00000017 RAX: 0000000000000101 RBX: 00000000ffffffff RCX: 0000000000000000 RDX: 0000000000000101 RSI: ffffc90000faf5d0 RDI: 0000000000000001 RBP: ffffc90000faf600 R08: ffffffff8df461e8 R09: 0000000000000001 R10: fffff520001f5e79 R11: 0000000000086089 R12: ffffc90000fa8000 R13: ffffc90000faf3a5 R14: ffffc90000faf370 R15: ffffc90000faf3a4 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005590073e97d0 CR3: 000000002902d000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xec8/0x1ce0 arch/x86/kernel/unwind_orc.c:611 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 save_stack+0x151/0x1e0 mm/page_owner.c:119 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2424 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4153 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5375 __alloc_pages_node include/linux/gfp.h:570 [inline] kmem_getpages mm/slab.c:1377 [inline] cache_grow_begin+0x75/0x460 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] slab_alloc_node mm/slab.c:3249 [inline] kmem_cache_alloc_node_trace+0x4ca/0x5d0 mm/slab.c:3617 __do_kmalloc_node mm/slab.c:3639 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3654 kmalloc_reserve net/core/skbuff.c:355 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 __netdev_alloc_skb+0x73/0x400 net/core/skbuff.c:493 netdev_alloc_skb include/linux/skbuff.h:2877 [inline] dev_alloc_skb include/linux/skbuff.h:2890 [inline] __ieee80211_beacon_get+0xdfa/0x1b20 net/mac80211/tx.c:5070 ieee80211_beacon_get_tim+0x88/0x930 net/mac80211/tx.c:5184 ieee80211_beacon_get include/net/mac80211.h:4981 [inline] mac80211_hwsim_beacon_tx+0x111/0x930 drivers/net/wireless/mac80211_hwsim.c:1808 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:920 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 0 CPU: 0 PID: 14903 Comm: syz-executor.2 Not tainted 5.15.0-rc2-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:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 99 ad 8c 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90000007d30 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000101 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff81647501 RDI: ffff88807a4d4c38 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8fd00937 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88807a4d4c10 R13: 1ffff92000000fa8 R14: ffffffff873b9550 R15: ffff8880b9c20240 call_timer_fn+0x10a/0x6b0 kernel/time/timer.c:1418 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4814 Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 03 be e8 07 e8 7e 2f 2c 00 fb 65 48 8b 1c 25 40 f0 01 00 <48> 8d bb 18 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900166d75a0 EFLAGS: 00000202 RAX: 00000000000000a1 RBX: ffff888080d52280 RCX: 1ffffffff1fa118a RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900166d75e0 R08: 0000000000000001 R09: ffffffff8fd00937 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b9c31ac0 R13: ffff88806b69e240 R14: 0000000000000000 R15: ffff8880b9c31ad8 context_switch kernel/sched/core.c:4943 [inline] __schedule+0x948/0x26f0 kernel/sched/core.c:6287 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 Code: 60 a7 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc900166d7790 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92002cdaef4 RCX: ffffffff815a46bf RDX: 1ffff110101aa58e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8fd00937 R10: fffffbfff1fa0126 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8babbc00 R15: 0000000000000000 fs_reclaim_acquire mm/page_alloc.c:4556 [inline] fs_reclaim_acquire+0xd2/0x160 mm/page_alloc.c:4547 might_alloc include/linux/sched/mm.h:198 [inline] slab_pre_alloc_hook mm/slab.h:492 [inline] slab_alloc_node mm/slab.c:3222 [inline] kmem_cache_alloc_node+0x47/0x590 mm/slab.c:3599 alloc_vmap_area+0x166/0x1e00 mm/vmalloc.c:1531 __get_vm_area_node.constprop.0+0x128/0x380 mm/vmalloc.c:2423 __vmalloc_node_range+0x12a/0x9e0 mm/vmalloc.c:3010 alloc_thread_stack_node kernel/fork.c:245 [inline] dup_task_struct kernel/fork.c:887 [inline] copy_process+0x926/0x7580 kernel/fork.c:2026 kernel_clone+0xe7/0xac0 kernel/fork.c:2584 __do_sys_fork+0x8a/0xc0 kernel/fork.c:2647 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: 0033:0x7f403d393709 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:00007f403a8c8188 EFLAGS: 00000246 ORIG_RAX: 0000000000000039 RAX: ffffffffffffffda RBX: 00007f403d4980e0 RCX: 00007f403d393709 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f403d3edcb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc0d1b5faf R14: 00007f403a8c8300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 85 c9 test %ecx,%ecx 2: 75 1b jne 0x1f 4: 65 8b 05 3e 27 b3 7e mov %gs:0x7eb3273e(%rip),%eax # 0x7eb32749 b: 89 c2 mov %eax,%edx d: 81 e2 ff ff ff 7f and $0x7fffffff,%edx 13: 39 da cmp %ebx,%edx 15: 7c 13 jl 0x2a 17: 81 fb fe 00 00 00 cmp $0xfe,%ebx 1d: 76 63 jbe 0x82 1f: f7 db neg %ebx 21: 65 01 1d 21 27 b3 7e add %ebx,%gs:0x7eb32721(%rip) # 0x7eb32749 * 28: 5b pop %rbx <-- trapping instruction 29: c3 retq 2a: e8 3a ce 87 02 callq 0x287ce69 2f: 85 c0 test %eax,%eax 31: 74 f5 je 0x28 33: 48 c7 c0 28 51 6e 8d mov $0xffffffff8d6e5128,%rax 3a: 48 rex.W 3b: ba .byte 0xba