rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31033/1:b..l (detected by 1, t=10503 jiffies, g=310773, q=33) task:syz-executor.1 state:R running task stack:29168 pid:31060 ppid: 8486 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 preempt_schedule_notrace+0x5b/0xd0 kernel/sched/core.c:6179 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36 rcu_is_watching+0x90/0xc0 kernel/rcu/tree.c:1161 rcu_read_lock include/linux/rcupdate.h:688 [inline] ext4_get_group_desc+0x14b/0x500 fs/ext4/balloc.c:284 recently_deleted fs/ext4/ialloc.c:683 [inline] find_inode_bit+0x1c4/0x580 fs/ext4/ialloc.c:729 __ext4_new_inode+0xc4d/0x5c40 fs/ext4/ialloc.c:1064 ext4_symlink+0x489/0xd50 fs/ext4/namei.c:3465 vfs_symlink fs/namei.c:4182 [inline] vfs_symlink+0x473/0x6a0 fs/namei.c:4167 do_symlinkat+0x27a/0x300 fs/namei.c:4212 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: 0033:0x465ee7 RSP: 002b:00007fff46191078 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000465ee7 RDX: 00007fff46191163 RSI: 00000000004bfd70 RDI: 00007fff46191150 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007fff46190f10 R10: 00007fff46190dc7 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff46191150 task:syz-executor.4 state:R running task stack:27528 pid:31033 ppid: 8492 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6328 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 cd c5 bb 7e 65 8b 05 c6 c5 bb 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 b5 29 09 00 e8 d0 80 35 00 fb 65 8b 05 a8 c5 bb 7e <85> c0 74 58 5b 5d c3 65 8b 05 f6 cc bb 7e 85 c0 75 a2 0f 0b eb 9e RSP: 0018:ffffc900025bf9e8 EFLAGS: 00000202 RAX: 0000000080000000 RBX: 00000000fffffe00 RCX: 1ffffffff1f9cac2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff88632a45 R08: 0000000000000001 R09: ffffffff8fccf8df R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000e1f R13: ffffc900025bfb80 R14: fffff520004b7f71 R15: 0000000000000000 nl80211_netlink_notify net/wireless/nl80211.c:17874 [inline] nl80211_netlink_notify+0x315/0x970 net/wireless/nl80211.c:17838 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 blocking_notifier_call_chain kernel/notifier.c:337 [inline] blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:325 netlink_release+0xcb8/0x1dd0 net/netlink/af_netlink.c:785 __sock_release+0xcd/0x280 net/socket.c:648 sock_close+0x18/0x20 net/socket.c:1300 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 get_signal+0x1b35/0x2160 kernel/signal.c:2581 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: 0033:0x4665d9 RSP: 002b:00007fcc207bd188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000033fe0 RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffc5edd24ef R14: 00007fcc207bd300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10556 jiffies! g310773 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:28864 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1878 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: 31061 Comm: syz-executor.5 Not tainted 5.14.0-rc1-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: 00000286 RAX: 00000000000029a5 RBX: ffff8880b9d52880 RCX: 0000000000000004 RDX: 0000000000000000 RSI: ffffed101738a511 RDI: ffff8880b9c52894 RBP: ffff8880b9c52894 R08: 0000000000000001 R09: ffff8880b9c52894 R10: ffffed101738a512 R11: 0000000000000080 R12: ffffed10173aa512 R13: ffff8880b9d52894 R14: dffffc0000000000 R15: ffff8880b9c52880 FS: 00007f9765457700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000088e6b000 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:6328 Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 e2 36 24 f8 e8 2d 7d 50 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 25 24 RSP: 0018:ffffc900027f7988 EFLAGS: 00000206 RAX: 00000000001963eb RBX: ffff888068f0b880 RCX: 1ffffffff1ad81a9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffed100d1e1710 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bab18 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:schedule+0xa/0x270 kernel/sched/core.c:6013 Code: 90 f8 48 c7 c7 60 6b 8b 89 e8 a6 3f bc ff e8 dd 85 90 f8 e9 5e e6 ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df <41> 55 41 54 55 65 48 8b 2c 25 00 f0 01 00 48 8d 7d 18 53 48 89 fa RSP: 0018:ffffc900027f7a58 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffff888068f0b880 RCX: ffffc9001461e000 RDX: 0000000000000000 RSI: ffffffff816963be RDI: ffff888068f0b8ac RBP: ffffc900027f7b88 R08: 0000000000000000 R09: ffffc90000e0740b R10: fffff520001c0e81 R11: 0000000000000000 R12: ffffc90000e07400 R13: 0000000000000000 R14: ffff888068f0b880 R15: 0000000000000000 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x25a/0x520 kernel/futex.c:2602 futex_wait+0x1db/0x5f0 kernel/futex.c:2704 do_futex+0x250/0x1770 kernel/futex.c:3730 __do_sys_futex+0xdc/0x3b0 kernel/futex.c:3807 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: 0033:0x4665d9 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:00007f9765457218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000056bf88 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88 RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffca538772f R14: 00007f9765457300 R15: 0000000000022000