rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 1, t=10502 jiffies, g=475653, q=530) rcu: All QSes seen, last rcu_preempt kthread activity 10465 (4295218984-4295208519), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10465 jiffies! g475653 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:28880 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 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: 3697 Comm: syz-executor.5 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:pv_wait_node kernel/locking/qspinlock_paravirt.h:301 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x5c4/0xb40 kernel/locking/qspinlock.c:473 Code: 32 84 c0 75 23 41 0f b6 14 24 4c 89 e9 83 e1 07 38 ca 7f 08 84 d2 0f 85 ed 03 00 00 0f b6 53 14 84 d2 0f 85 9e 00 00 00 f3 90 <83> e8 01 0f 84 93 00 00 00 0f b6 16 84 d2 74 09 80 fa 03 0f 8e 96 RSP: 0018:ffffc90000007a30 EFLAGS: 00000282 RAX: 00000000000062a2 RBX: ffff8880b9d52840 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffed101738a509 RDI: ffff8880b9c52854 RBP: ffff8880b9c52854 R08: 0000000000000001 R09: ffff8880b9c52854 R10: ffffed101738a50a R11: 0000000000000080 R12: ffffed10173aa50a R13: ffff8880b9d52854 R14: dffffc0000000000 R15: ffff8880b9c52840 FS: 00007f34c16bb700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3e33f56ef0 CR3: 00000000b1ac4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113 spin_lock include/linux/spinlock.h:354 [inline] mac80211_hwsim_tx_frame_no_nl.isra.0+0x68f/0x1330 drivers/net/wireless/mac80211_hwsim.c:1516 mac80211_hwsim_tx_frame+0x1ee/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1784 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:1537 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 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:1100 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:6326 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 e2 26 1e f8 e8 fd 72 4a 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 f0 15 1e RSP: 0018:ffffc9000192f4c8 EFLAGS: 00000206 RAX: 00000000000105d1 RBX: ffff888020c1b880 RCX: 1ffffffff1ad95d9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffed1004183710 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bd418 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:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:390 Code: 1d ad a3 bb 7e 65 8b 05 a6 a3 bb 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 85 2a 09 00 e8 70 87 35 00 fb 65 8b 05 88 a3 bb 7e <85> c0 74 58 5b 5d c3 65 8b 05 d6 aa bb 7e 85 c0 75 a2 0f 0b eb 9e RSP: 0018:ffffc9000192f590 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 00000000fffffe01 RCX: 1ffffffff1ad95d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff871abd2e R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bd418 R11: 0000000000000001 R12: ffff88802b8c3cc0 R13: ffff88802b8c3c00 R14: ffff88807d8860e0 R15: 0000000000001000 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:757 [inline] __dev_queue_xmit+0x1bbc/0x3710 net/core/dev.c:4229 __bpf_tx_skb net/core/filter.c:2114 [inline] __bpf_redirect_no_mac net/core/filter.c:2139 [inline] __bpf_redirect+0x5ba/0xd20 net/core/filter.c:2162 ____bpf_clone_redirect net/core/filter.c:2429 [inline] bpf_clone_redirect+0x2ae/0x420 net/core/filter.c:2401 bpf_prog_eb4214e34d195ba1+0x58/0x938 bpf_dispatcher_nop_func include/linux/bpf.h:717 [inline] __bpf_prog_run include/linux/filter.h:626 [inline] bpf_prog_run include/linux/filter.h:633 [inline] bpf_test_run+0x381/0xa30 net/bpf/test_run.c:119 bpf_prog_test_run_skb+0xac5/0x1d20 net/bpf/test_run.c:657 bpf_prog_test_run kernel/bpf/syscall.c:3307 [inline] __sys_bpf+0x2137/0x5df0 kernel/bpf/syscall.c:4605 __do_sys_bpf kernel/bpf/syscall.c:4691 [inline] __se_sys_bpf kernel/bpf/syscall.c:4689 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4689 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:00007f34c16bb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000048 RSI: 0000000020000780 RDI: 000000000000000a RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffea0babb4f R14: 00007f34c16bb300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 32 84 c0 75 23 41 0f xor 0xf412375(%rax,%rax,8),%al 7: b6 14 mov $0x14,%dh 9: 24 4c and $0x4c,%al b: 89 e9 mov %ebp,%ecx d: 83 e1 07 and $0x7,%ecx 10: 38 ca cmp %cl,%dl 12: 7f 08 jg 0x1c 14: 84 d2 test %dl,%dl 16: 0f 85 ed 03 00 00 jne 0x409 1c: 0f b6 53 14 movzbl 0x14(%rbx),%edx 20: 84 d2 test %dl,%dl 22: 0f 85 9e 00 00 00 jne 0xc6 28: f3 90 pause * 2a: 83 e8 01 sub $0x1,%eax <-- trapping instruction 2d: 0f 84 93 00 00 00 je 0xc6 33: 0f b6 16 movzbl (%rsi),%edx 36: 84 d2 test %dl,%dl 38: 74 09 je 0x43 3a: 80 fa 03 cmp $0x3,%dl 3d: 0f .byte 0xf 3e: 8e .byte 0x8e 3f: 96 xchg %eax,%esi