rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=8f64/1/0x4000000000000000 softirq=27713/27720 fqs=182
rcu: (detected by 0, t=10502 jiffies, g=17553, q=1236 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7867 Comm: syz.2.887 Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:check_preemption_disabled+0x0/0xe0 lib/smp_processor_id.c:13
Code: c0 75 0f 65 8b 05 cc 5e 34 08 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 54 55 53 48 83 ec 08 65 8b 1d 85 24 34 08 65 8b 05 7a 24 34 08
RSP: 0018:ffffc90000a08ce8 EFLAGS: 00000087
RAX: 0000000000000001 RBX: ffff8880338c6300 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8bf46540 RDI: ffffffff8bf46580
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f94e49bd6c0(0000) GS:ffff888124ab2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fa1eff8 CR3: 000000007a9e0000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:736
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x2cd/0x350 kernel/locking/lockdep.c:5829
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:924
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5891
Code: 0f c1 05 08 f3 0e 12 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 5d b5 0e 12 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc9000370fc40 EFLAGS: 00000206
RAX: e442211f80a4e700 RBX: ffffc90000a6b520 RCX: ffffc9000370fc4c
RDX: 0000000000000000 RSI: ffffffff8dbca29f RDI: ffffffff8bf465c0
RBP: ffffc90000a6b530 R08: 0000000000000004 R09: 00000000000f4240
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81aeda52
R13: 0000000000000202 R14: ffff888069d3a440 R15: 0000000000000001
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
futex_wake+0x432/0x4e0 kernel/futex/waitwake.c:198
do_futex+0x1e3/0x350 kernel/futex/syscalls.c:107
__do_sys_futex kernel/futex/syscalls.c:179 [inline]
__se_sys_futex kernel/futex/syscalls.c:160 [inline]
__x64_sys_futex+0x1e0/0x4c0 kernel/futex/syscalls.c:160
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f94e3b8e169
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f94e49bd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f94e3db5fa8 RCX: 00007f94e3b8e169
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f94e3db5fac
RBP: 00007f94e3db5fa0 R08: 00007f94e49be000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f94e3db5fac
R13: 0000000000000000 R14: 00007fff4870dc70 R15: 00007fff4870dd58
rcu: rcu_preempt kthread starved for 10138 jiffies! g17553 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:27304 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x4aa/0x1290 kernel/smp.c:885
Code: 0c 00 85 ed 74 48 48 8b 44 24 20 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 5d 17 0c 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 de 0b 00 00 8b 43 08 31 ff 83 e0 01 41
RSP: 0018:ffffc90000116870 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b853f740 RCX: ffffffff81af38b9
RDX: ffff88801c6fc880 RSI: ffffffff81af3893 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170a7ee9
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b843b040
FS: 0000000000000000(0000) GS:ffff8881249b2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557646f5c8 CR3: 000000002d636000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline]
flush_tlb_mm_range+0x322/0x1780 arch/x86/mm/tlb.c:1365
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x136/0x180 mm/pgtable-generic.c:101
page_vma_mkclean_one.constprop.0+0x3b4/0x7e0 mm/rmap.c:1059
page_mkclean_one+0x183/0x230 mm/rmap.c:1100
__rmap_walk_file+0x356/0x620 mm/rmap.c:2897
rmap_walk_file+0x174/0x1f0 mm/rmap.c:2930
rmap_walk mm/rmap.c:2941 [inline]
folio_mkclean+0x251/0x3f0 mm/rmap.c:1132
folio_clear_dirty_for_io+0x153/0x810 mm/page-writeback.c:2987
mpage_submit_folio+0x80/0x350 fs/ext4/inode.c:1918
mpage_process_page_bufs+0x47c/0x9a0 fs/ext4/inode.c:2050
mpage_prepare_extent_to_map+0x759/0x1460 fs/ext4/inode.c:2551
ext4_do_writepages+0x9af/0x3490 fs/ext4/inode.c:2692
ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2829
do_writepages+0x1b2/0x820 mm/page-writeback.c:2656
__writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2047
wb_writeback+0x7f3/0xb70 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0x8ca/0xbe0 fs/fs-writeback.c:2343
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245