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=574917, q=15) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4295301141-4295290641), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g574917 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:29184 pid: 13 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4324 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5075 schedule+0xcf/0x270 kernel/sched/core.c:5154 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline] rcu_gp_kthread+0xd07/0x2250 kernel/rcu/tree.c:2178 kthread+0x3b1/0x4a0 kernel/kthread.c:292 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7004 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:121 [inline] RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:435 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3c4/0xb40 kernel/locking/qspinlock.c:508 Code: 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 85 91 05 00 00 0f b6 45 00 84 RSP: 0018:ffffc90000007a38 EFLAGS: 00000202 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffffffff21218c4 RDX: 0000000000000001 RSI: ffffffff81793841 RDI: ffffffff8131d487 RBP: ffffffff9090c620 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff81793809 R11: 0000000000000080 R12: 0000000000007445 R13: fffffbfff21218c4 R14: 0000000000000001 R15: ffff8880b9c35f40 FS: 00007f48a87d4700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e397b1718 CR3: 000000007ef65000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [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:1514 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:1519 [inline] __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 invoke_softirq kernel/softirq.c:221 [inline] __irq_exit_rcu kernel/softirq.c:422 [inline] irq_exit_rcu+0x134/0x200 kernel/softirq.c:434 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:5532 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 22 e9 49 f8 e8 2d 36 75 f8 fb bf 01 00 00 00 a2 d0 ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 60 d7 49 RSP: 0018:ffffc9000281eea8 EFLAGS: 00000202 RAX: 0000000000006ff7 RBX: ffff88802b9d1bc0 RCX: 1ffffffff1f5caea RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffed100573a378 R08: 0000000000000001 R09: ffffffff8faae8f7 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit_cond_resched kernel/entry/common.c:392 [inline] irqentry_exit_cond_resched kernel/entry/common.c:384 [inline] irqentry_exit+0x7a/0xa0 kernel/entry/common.c:428 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632 RIP: 0010:ext4_mb_new_blocks+0x2479/0x51a0 fs/ext4/mballoc.c:4975 Code: 0c 84 d2 74 08 48 89 cf e8 44 a7 a9 ff 48 8b 44 24 10 c7 00 00 00 00 00 e8 04 c7 65 ff 4c 89 f7 e8 3c 50 ff ff 48 8b 4c 24 10 <89> c3 48 b8 00 00 00 00 00 fc ff df 48 89 ca 48 c1 ea 03 0f b6 14 RSP: 0018:ffffc9000281ef70 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff8880628e1a80 RCX: ffffc9000281f1f0 RDX: 0000000000040000 RSI: ffffffff820ce69e RDI: 0000000000000003 RBP: ffff8880628e1af0 R08: 0000000000000000 R09: 0000000000000002 R10: ffffffff820ce680 R11: 0000000000000002 R12: 0000000000002420 R13: ffff8880221a6000 R14: ffff8880676e56c0 R15: ffffc9000281f200 ext4_alloc_branch fs/ext4/indirect.c:333 [inline] ext4_ind_map_blocks+0x196a/0x2450 fs/ext4/indirect.c:626 ext4_map_blocks+0x9c9/0x17d0 fs/ext4/inode.c:640 mpage_map_one_extent fs/ext4/inode.c:2397 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2450 [inline] ext4_writepages+0x1cb7/0x3b70 fs/ext4/inode.c:2802 do_writepages+0xec/0x290 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x2a5/0x390 mm/filemap.c:424 filemap_write_and_wait_range mm/filemap.c:657 [inline] filemap_write_and_wait_range+0xe1/0x1c0 mm/filemap.c:651 __iomap_dio_rw+0x5aa/0x1280 fs/iomap/direct-io.c:525 iomap_dio_rw+0x30/0x90 fs/iomap/direct-io.c:641 ext4_dio_write_iter fs/ext4/file.c:551 [inline] ext4_file_write_iter+0xe18/0x14e0 fs/ext4/file.c:661 call_write_iter include/linux/fs.h:1977 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x796/0xa30 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x465f69 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:00007f48a87d4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000043408 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 00000000004bfa67 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffc512a475f R14: 00007f48a87d4300 R15: 0000000000022000