rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 0, t=10502 jiffies, g=675257, q=392) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4295295669-4295285169), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g675257 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: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: 16124 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:mac80211_hwsim_tx_frame_no_nl.isra.0+0x78f/0x1330 drivers/net/wireless/mac80211_hwsim.c:1525 Code: 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 44 89 fe e8 27 82 4c fc 45 84 ff 0f 84 77 ff ff ff e8 69 7b RSP: 0018:ffffc90000dc0ba0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888092e4b1e0 RCX: 0000000000000100 RDX: 0000000000000004 RSI: ffffffff85284703 RDI: ffff888092e4ee84 RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000000 R10: ffffffff85284739 R11: 0000000000000000 R12: ffff888070cc7c80 R13: ffff88801d123410 R14: ffff88801d1231e0 R15: 0000000000000000 FS: 00007fb5a04b8700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5a0476718 CR3: 000000002f8e4000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:5535 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 72 96 36 f8 e8 9d 6d 62 f8 fb bf 01 00 00 00 92 ce ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 c0 84 36 RSP: 0018:ffffc90002b3f5d8 EFLAGS: 00000202 RAX: 0000000000003551 RBX: ffff888020c13880 RCX: 1ffffffff2054bca RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffed1004182710 R08: 0000000000000001 R09: ffffffff9025f95f R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x31/0x80 kernel/entry/common.c:426 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:lock_is_held_type+0xfd/0x140 kernel/locking/lockdep.c:5560 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6e 2c eb 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc90002b3f6a8 EFLAGS: 00000282 RAX: 0000000000000046 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8bf796a0 R08: 0000000000000097 R09: 0000000000000001 R10: ffffffff820c6d26 R11: 0000000000000000 R12: ffff888020c13880 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888020c14278 lock_is_held include/linux/lockdep.h:283 [inline] ___might_sleep+0x23f/0x2c0 kernel/sched/core.c:8304 lock_page include/linux/pagemap.h:623 [inline] mpage_prepare_extent_to_map+0x46b/0xe20 fs/ext4/inode.c:2600 ext4_writepages+0x11cf/0x3b70 fs/ext4/inode.c:2798 do_writepages+0xec/0x290 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x2a5/0x390 mm/filemap.c:413 ext4_alloc_da_blocks+0x1ed/0x330 fs/ext4/inode.c:3164 ext4_release_file+0x183/0x370 fs/ext4/file.c:141 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x272/0x280 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57 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:00007fb5a04b8188 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000056c038 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffed6552e7f R14: 00007fb5a04b8300 R15: 0000000000022000