rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=479321, q=4) rcu: All QSes seen, last rcu_preempt kthread activity 10496 (4295224224-4295213728), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10496 jiffies! g479321 f0x2 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: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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 31263 Comm: syz-executor.3 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x78/0x80 kernel/kcov.c:272 Code: 72 27 41 0f b6 fb 41 0f b6 c9 48 83 c2 01 48 c7 44 30 e0 01 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b 0f 1f 80 00 00 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 RSP: 0018:ffffc90000dc0998 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88801b919c40 RDX: 0000000000000000 RSI: ffff88801b919c40 RDI: 0000000000000003 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8196c0c4 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88806ad4bff0 R14: ffffc9000129f6b8 R15: 0000000000000008 FS: 00007f0cc4492700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000204001ff CR3: 000000008f238000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:716 [inline] __perf_output_begin kernel/events/ring_buffer.c:259 [inline] perf_output_begin_forward+0x4b4/0xae0 kernel/events/ring_buffer.c:268 __perf_event_output kernel/events/core.c:7450 [inline] perf_event_output_forward+0xf2/0x280 kernel/events/core.c:7468 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9140 perf_swevent_hrtimer+0x37c/0x3f0 kernel/events/core.c:10540 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe50 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+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 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:ffffc9000129f768 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff11028fe9220 RDX: 0000000000000001 RSI: ffffffff817bacb1 RDI: ffffffff81330591 RBP: ffff888147f49100 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bac79 R11: 0000000000000000 R12: 00000000000049ea R13: ffffed1028fe9220 R14: 0000000000000001 R15: ffff8880b9d52880 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] ext4_lock_group+0x1e5/0x240 fs/ext4/ext4.h:3456 ext4_discard_preallocations+0x5d3/0xee0 fs/ext4/mballoc.c:4957 ext4_punch_hole+0x5f9/0x1110 fs/ext4/inode.c:4103 ext4_fallocate+0x1175/0x3ff0 fs/ext4/extents.c:4662 vfs_fallocate+0x48d/0xd80 fs/open.c:311 ioctl_preallocate+0x18e/0x200 fs/ioctl.c:497 file_ioctl fs/ioctl.c:540 [inline] do_vfs_ioctl+0x112a/0x15d0 fs/ioctl.c:1048 __do_sys_ioctl fs/ioctl.c:1067 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x108/0x200 fs/ioctl.c:1055 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: 0033:0x4665e9 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:00007f0cc4492188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000020000040 RSI: 0000000040305829 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffcfdb2059f R14: 00007f0cc4492300 R15: 0000000000022000 ================================ WARNING: inconsistent lock state 5.14.0-rc2-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz-executor.2/31264 [HC0[0]:SC1[1]:HE0:SE0] takes: ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:543 [inline] ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:709 [inline] ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3922 [inline] ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc9a/0x20c0 kernel/rcu/tree.c:2641 {IN-HARDIRQ-W} state was registered at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 rcu_report_exp_cpu_mult+0x1c/0x280 kernel/rcu/tree_exp.h:237 flush_smp_call_function_queue+0x34b/0x640 kernel/smp.c:663 __sysvec_call_function_single+0x95/0x3d0 arch/x86/kernel/smp.c:248 sysvec_call_function_single+0x8e/0xc0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:646 debug_object_init+0x0/0x20 lib/debugobjects.c:277 __init_work+0x48/0x50 kernel/workqueue.c:504 call_usermodehelper_setup+0xb2/0x340 kernel/umh.c:369 kobject_uevent_env+0xf73/0x1650 lib/kobject_uevent.c:614 version_sysfs_builtin kernel/params.c:860 [inline] param_sysfs_init+0x146/0x498 kernel/params.c:951 do_one_initcall+0x103/0x650 init/main.c:1282 do_initcall_level init/main.c:1355 [inline] do_initcalls init/main.c:1371 [inline] do_basic_setup init/main.c:1391 [inline] kernel_init_freeable+0x6b8/0x741 init/main.c:1593 kernel_init+0x1a/0x1d0 init/main.c:1485 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 irq event stamp: 9981597 hardirqs last enabled at (9981596): [] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 hardirqs last disabled at (9981597): [] sysvec_apic_timer_interrupt+0xb/0xc0 arch/x86/kernel/apic/apic.c:1100 softirqs last enabled at (3881680): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (3881680): [] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 softirqs last disabled at (3881683): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (3881683): [] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rcu_node_0); lock(rcu_node_0); *** DEADLOCK *** 7 locks held by syz-executor.2/31264: #0: ffff888028eb8460 (sb_writers#5){.+.+}-{0:0}, at: ioctl_preallocate+0x18e/0x200 fs/ioctl.c:497 #1: ffff888028ebab40 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0xec/0x290 mm/page-writeback.c:2355 #2: ffff88806b815238 (&ei->i_data_sem){++++}-{3:3}, at: ext4_map_blocks+0x5e1/0x17d0 fs/ext4/inode.c:631 #3: ffff888147f49118 (&bgl->locks[i].lock){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:364 [inline] #3: ffff888147f49118 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_lock_group fs/ext4/ext4.h:3443 [inline] #3: ffff888147f49118 (&bgl->locks[i].lock){+.+.}-{2:2}, at: ext4_mb_regular_allocator+0xbd1/0x3870 fs/ext4/mballoc.c:2740 #4: ffffffff8b97b9c0 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_active_interfaces_atomic+0x0/0x180 net/mac80211/util.c:1237 #5: ffffffff8c77c4f8 (hwsim_radio_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] #5: ffffffff8c77c4f8 (hwsim_radio_lock){+.-.}-{2:2}, at: mac80211_hwsim_tx_frame_no_nl.isra.0+0x68f/0x1330 drivers/net/wireless/mac80211_hwsim.c:1516 #6: ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:543 [inline] #6: ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:709 [inline] #6: ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3922 [inline] #6: ffffffff8b984818 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0xc9a/0x20c0 kernel/rcu/tree.c:2641 stack backtrace: CPU: 0 PID: 31264 Comm: syz-executor.2 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_usage_bug kernel/locking/lockdep.c:203 [inline] valid_state kernel/locking/lockdep.c:3933 [inline] mark_lock_irq kernel/locking/lockdep.c:4136 [inline] mark_lock.cold+0x61/0x8e kernel/locking/lockdep.c:4593 mark_held_locks+0x9f/0xe0 kernel/locking/lockdep.c:4194 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4212 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4280 [inline] lockdep_hardirqs_on_prepare+0x135/0x400 kernel/locking/lockdep.c:4232 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:mac80211_hwsim_tx_frame_no_nl.isra.0+0x737/0x1330 drivers/net/wireless/mac80211_hwsim.c:1517 Code: b6 44 24 08 84 c0 0f 85 a8 06 00 00 e8 82 95 43 fc e8 7d 95 43 fc 48 89 d8 48 c1 e8 03 80 3c 28 00 0f 85 93 09 00 00 48 8b 1b <48> 81 fb a0 c4 77 8c 0f 84 f7 04 00 00 e8 57 95 43 fc 49 39 de 4c RSP: 0018:ffffc90000007ba0 EFLAGS: 00000246 RAX: 1ffff1100302464c RBX: ffff88803d723260 RCX: 0000000000000100 RDX: ffff888023a21c40 RSI: ffffffff8531f3c3 RDI: 0000000000000003 RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffffff8531f439 R11: 0000000000000000 R12: ffff88809ccd0280 R13: ffff88806b403490 R14: ffff88806b403260 R15: 0000000000000000 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:ext4_mb_simple_scan_group+0x1e/0x6c0 fs/ext4/mballoc.c:2261 Code: ff 66 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 41 55 41 54 49 bc 00 00 00 00 00 fc ff df 55 48 89 f5 53 48 89 fb 48 83 c4 80 <48> c7 44 24 20 b3 8a b5 41 48 8d 44 24 20 48 c7 44 24 28 97 b2 15 RSP: 0018:ffffc9000163ecb0 EFLAGS: 00000283 RAX: 000000000000c5dc RBX: ffff888095656d00 RCX: ffffc9000e342000 RDX: 0000000000040000 RSI: ffffc9000163eea0 RDI: ffff888095656d00 RBP: ffffc9000163eea0 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8213f3ab R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888028eba624 R14: 0000000000000000 R15: ffff888095656d00 ext4_mb_regular_allocator+0x1a76/0x3870 fs/ext4/mballoc.c:2755 ext4_mb_new_blocks+0x24d4/0x5230 fs/ext4/mballoc.c:5515 ext4_ext_map_blocks+0x1fa3/0x6070 fs/ext4/extents.c:4245 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:638 mpage_map_one_extent fs/ext4/inode.c:2395 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2448 [inline] ext4_writepages+0x1d01/0x3ba0 fs/ext4/inode.c:2800 do_writepages+0xec/0x290 mm/page-writeback.c:2355 __filemap_fdatawrite_range+0x2a5/0x390 mm/filemap.c:413 filemap_write_and_wait_range mm/filemap.c:686 [inline] filemap_write_and_wait_range+0x65/0x100 mm/filemap.c:680 ext4_punch_hole+0x1f4/0x1110 fs/ext4/inode.c:4020 ext4_fallocate+0x1175/0x3ff0 fs/ext4/extents.c:4662 vfs_fallocate+0x48d/0xd80 fs/open.c:311 ioctl_preallocate+0x18e/0x200 fs/ioctl.c:497 file_ioctl fs/ioctl.c:540 [inline] do_vfs_ioctl+0x112a/0x15d0 fs/ioctl.c:1048 __do_sys_ioctl fs/ioctl.c:1067 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x108/0x200 fs/ioctl.c:1055 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: 0033:0x4665e9 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:00007f04464ca188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9 RDX: 0000000020000040 RSI: 0000000040305829 RDI: 0000000000000004 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffe88d19ccf R14: 00007f04464ca300 R15: 0000000000022000 softirq: huh, entered softirq 8 HRTIMER ffffffff816555f0 with preempt_count 00000101, exited with 00000102?