rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=f62/1/0x4000000000000000 softirq=140065/140073 fqs=1 (t=10500 jiffies g=274157 q=30) rcu: rcu_preempt kthread timer wakeup didn't happen for 10476 jiffies! g274157 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=98676 rcu: rcu_preempt kthread starved for 10477 jiffies! g274157 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28816 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4339 [inline] __schedule+0x916/0x23e0 kernel/sched/core.c:5147 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2004 [inline] rcu_gp_kthread+0xd07/0x2300 kernel/rcu/tree.c:2177 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 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: 31826 Comm: syz-executor.2 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: 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 40 00 65 8b 05 09 2d 8d 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 00 f0 01 00 a9 RSP: 0018:ffffc9000166f820 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff888066c6b880 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff8880123c8e07 R10: ffffffff817acf79 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc700943700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014a53ad CR3: 0000000075378000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: preempt_count arch/x86/include/asm/preempt.h:27 [inline] trace_hardirqs_on+0x22/0x1c0 kernel/trace/trace_preemptirq.c:43 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508 Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f RSP: 0018:ffffc9000166f8f0 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff1100355d9e9 RDX: 0000000000000001 RSI: ffffffff817acfb1 RDI: ffffffff8132b571 RBP: ffff88801aaecf48 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817acf79 R11: 0000000000000000 R12: 00000000000042f1 R13: ffffed100355d9e9 R14: 0000000000000001 R15: ffff8880b9d36040 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] __find_get_block_slow fs/buffer.c:206 [inline] __find_get_block fs/buffer.c:1333 [inline] __find_get_block+0x4df/0xda0 fs/buffer.c:1327 sb_find_get_block include/linux/buffer_head.h:340 [inline] recently_deleted fs/ext4/ialloc.c:686 [inline] find_inode_bit+0x230/0x580 fs/ext4/ialloc.c:728 __ext4_new_inode+0xc4d/0x5600 fs/ext4/ialloc.c:1063 ext4_mkdir+0x33a/0xb20 fs/ext4/namei.c:2919 vfs_mkdir+0x538/0x770 fs/namei.c:3813 do_mkdirat+0x284/0x310 fs/namei.c:3838 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 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:00007fc700943188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffc8db1a1bf R14: 00007fc700943300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 31827 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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:341 print_cpu_stall kernel/rcu/tree_stall.h:624 [inline] check_cpu_stall kernel/rcu/tree_stall.h:699 [inline] rcu_pending kernel/rcu/tree.c:3911 [inline] rcu_sched_clock_irq.cold+0x3f1/0x74b kernel/rcu/tree.c:2649 update_process_times+0x16d/0x200 kernel/time/timer.c:1796 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1373 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:mac80211_hwsim_tx_frame_no_nl.isra.0+0x77b/0x1330 drivers/net/wireless/mac80211_hwsim.c:1525 Code: 00 00 00 c6 84 24 98 00 00 00 00 74 bb e8 4d 7c 4c fc 48 8d bb a4 3c 00 00 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 0f b6 04 28 <38> d0 7f 08 84 c0 0f 85 36 09 00 00 44 0f b6 bb a4 3c 00 00 31 ff RSP: 0018:ffffc90000007ba0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88807ca731e0 RCX: 0000000000000100 RDX: 0000000000000004 RSI: ffffffff85284663 RDI: ffff88807ca76e84 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff85284699 R11: 0000000000000000 R12: ffff88808359c780 R13: ffff88803202b410 R14: ffff88803202b1e0 R15: 0000000000000000 mac80211_hwsim_tx_frame+0x14f/0x1e0 drivers/net/wireless/mac80211_hwsim.c:1775 mac80211_hwsim_beacon_tx+0x4ba/0x910 drivers/net/wireless/mac80211_hwsim.c:1829 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x8d/0x170 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1852 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9f6 kernel/softirq.c:559 invoke_softirq kernel/softirq.c:433 [inline] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 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:632 RIP: 0010:check_kcov_mode+0xf/0x40 kernel/kcov.c:163 Code: 41 45 00 e9 a1 fe ff ff 48 8b 3c 24 e8 0a 41 45 00 e9 18 fe ff ff cc cc cc cc cc 65 8b 05 49 35 8d 7e 89 c2 81 e2 00 01 00 00 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b 96 3c 15 00 00 85 d2 74 RSP: 0018:ffffc9000169fa48 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000001 RCX: ffff888027639c40 RDX: 0000000000000000 RSI: ffff888027639c40 RDI: 0000000000000003 RBP: ffffea00018cc440 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff81d5b5e8 R11: 0000000000000000 R12: 0000000000000394 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880375c11d0 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:270 __find_get_block_slow fs/buffer.c:207 [inline] __find_get_block fs/buffer.c:1333 [inline] __find_get_block+0x558/0xda0 fs/buffer.c:1327 sb_find_get_block include/linux/buffer_head.h:340 [inline] recently_deleted fs/ext4/ialloc.c:686 [inline] find_inode_bit+0x230/0x580 fs/ext4/ialloc.c:728 __ext4_new_inode+0xc4d/0x5600 fs/ext4/ialloc.c:1063 ext4_mkdir+0x33a/0xb20 fs/ext4/namei.c:2919 vfs_mkdir+0x538/0x770 fs/namei.c:3813 do_mkdirat+0x284/0x310 fs/namei.c:3838 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 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:00007fecfcb91188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000200 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fff3619c07f R14: 00007fecfcb91300 R15: 0000000000022000