rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10290 ticks this GP) idle=331/1/0x4000000000000000 softirq=37818/37819 fqs=322 (t=10501 jiffies g=48865 q=2524) rcu: rcu_preempt kthread starved for 2889 jiffies! g48865 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:28736 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22310 Comm: syz-executor.2 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__ieee80211_beacon_get+0xcbf/0x1b20 net/mac80211/tx.c:5059 Code: f8 48 8d bb 00 fb ff ff 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e2 0c 00 00 48 8b ab 00 fb ff ff 4c eb d2 f8 31 ff 41 89 c4 89 c6 e8 70 c8 e7 f8 45 85 e4 0f 84 RSP: 0018:ffffc90000007b78 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff88805f84a080 RCX: 0000000000000100 RDX: 1ffff1100bf09370 RSI: ffffffff888e5696 RDI: ffff88805f849b80 RBP: ffff888021e8f800 R08: 0000000000000001 R09: ffffc90000007cc0 R10: ffffffff888e4be8 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888064468d60 R14: 0000000000000000 R15: ffffc90000007cc0 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b0291cba50 CR3: 000000000b68e000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: 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 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: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 f9 d7 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc900035b77a8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888018eb1c80 RDX: 0000000000000000 RSI: ffff888018eb1c80 RDI: 0000000000000003 RBP: ffffea00013c5c80 R08: 0000000000000042 R09: 0000000000000000 R10: ffffffff81ab0cd7 R11: 0000000000000000 R12: ffffea00013c5cb0 R13: 0000000000000000 R14: dffffc0000000000 R15: 00007f89ceab9000 zap_pte_range mm/memory.c:1414 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xa45/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3195 __mmput+0x122/0x470 kernel/fork.c:1103 mmput+0x58/0x60 kernel/fork.c:1124 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007f89cc879188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: fffffffffffffdfe RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fff74a05a7f R14: 00007f89cc879300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 22295 Comm: syz-executor.3 Not tainted 5.14.0-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:105 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:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: 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 f9 d7 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 RSP: 0018:ffffc90000dc07c0 EFLAGS: 00000246 RAX: 0000000000000101 RBX: 0000000000000000 RCX: 0000000000000100 RDX: ffff888025bb8000 RSI: ffffffff81821c3c RDI: ffffffff8d0e7d80 RBP: 00000000004665f9 R08: 00000000004665f9 R09: 0000000000000001 R10: ffffffff81821c13 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffffa004e000 do_read_seqcount_retry include/linux/seqlock.h:452 [inline] read_seqcount_latch_retry include/linux/seqlock.h:699 [inline] latch_tree_find include/linux/rbtree_latch.h:209 [inline] bpf_ksym_find+0x5d/0x1c0 kernel/bpf/core.c:673 is_bpf_text_address+0x58/0x170 kernel/bpf/core.c:707 kernel_text_address kernel/extable.c:151 [inline] kernel_text_address+0xbd/0xf0 kernel/extable.c:120 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:318 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:313 arch_stack_walk+0x93/0xe0 arch/x86/kernel/stacktrace.c:26 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:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kmem_cache_free+0x8a/0x5b0 mm/slub.c:3229 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:699 __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:911 [inline] consume_skb+0xcf/0x160 net/core/skbuff.c:905 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1785 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838 __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 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:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:6687 Code: 55 53 65 48 8b 1c 25 40 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 42 5b 1a f8 e8 4d e8 46 f8 fb bf 01 00 00 00 d2 cd ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 40 4a 1a RSP: 0018:ffffc900035674f8 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff888025bb8000 RCX: 1ffffffff1add0dd RDX: 0000000000000000 RSI: ffffffff817c4071 RDI: 0000000000000001 RBP: ffffed1004b77000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817c4058 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:rcu_read_unlock_sched_notrace include/linux/rcupdate.h:809 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline] RIP: 0010:lock_acquire+0x44d/0x510 kernel/locking/lockdep.c:5596 Code: ff ff e8 05 d0 a4 ff e9 59 fc ff ff 65 ff 05 ea 79 a6 7e 48 8b 05 a3 b3 fe 0b e8 8e cc 05 00 85 c0 74 17 65 ff 0d d3 79 a6 7e <0f> 85 78 fc ff ff e8 d7 cf a4 ff e9 6e fc ff ff e8 ae 54 d8 07 85 RSP: 0018:ffffc900035675c8 EFLAGS: 00000286 RAX: 0000000000000001 RBX: 1ffff920006acebb RCX: ffffffff815b7298 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8d6e53d0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8d6e53d7 R10: fffffbfff1adca7a R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8b97f8e0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] __fget_files+0x4d/0x3e0 fs/file.c:849 __fget fs/file.c:870 [inline] __fget_light fs/file.c:965 [inline] __fget_light+0xd4/0x280 fs/file.c:954 fdget include/linux/file.h:65 [inline] do_select+0xa65/0x16a0 fs/select.c:530 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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: 0033:0x4665f9 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:00007fabd10f3188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffd84fe538f R14: 00007fabd10f3300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: f8 clc 1: 48 8d bb 00 fb ff ff lea -0x500(%rbx),%rdi 8: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax f: fc ff df 12: 48 89 fa mov %rdi,%rdx 15: 48 c1 ea 03 shr $0x3,%rdx 19: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 1d: 0f 85 e2 0c 00 00 jne 0xd05 23: 48 8b ab 00 fb ff ff mov -0x500(%rbx),%rbp * 2a: e8 4c eb d2 f8 callq 0xf8d2eb7b <-- trapping instruction 2f: 31 ff xor %edi,%edi 31: 41 89 c4 mov %eax,%r12d 34: 89 c6 mov %eax,%esi 36: e8 70 c8 e7 f8 callq 0xf8e7c8ab 3b: 45 85 e4 test %r12d,%r12d 3e: 0f .byte 0xf 3f: 84 .byte 0x84