rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10907 jiffies, g=8577, q=764 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10907 (4294957452-4294946545), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10907 jiffies! g8577 f0x2 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:28136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5598 [inline]
RIP: 0010:lock_is_held_type+0x87/0x150 kernel/locking/lockdep.c:5940
Code: b1 8d 4d 8d ac 24 30 0b 00 00 45 31 ff e8 01 15 00 00 65 ff 05 72 2b 41 08 41 8b 84 24 28 0b 00 00 85 c0 7f 17 e9 92 00 00 00 <41> 83 c7 01 45 3b bc 24 28 0b 00 00 0f 8d 80 00 00 00 49 63 c7 48
RSP: 0018:ffffc90000007d50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88801d6a0ba8 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff88803300b300 RDI: ffff88801d6a0ba8
RBP: ffff88803300b300 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801d6a0000
R13: ffff88801d6a0b30 R14: 00000000ffffffff R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888124a08000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 00000000320a3000 CR4: 00000000003526f0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
advance_sched+0x83b/0xc80 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x1600 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 e5 0c 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31
RSP: 0018:ffffc900001268a8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8540320 RCX: ffffffff81b0dc11
RDX: ffff88801d6a0000 RSI: ffffffff81b0dbeb RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed10170a8065 R14: 0000000000000001 R15: 0000000000000001
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline]
flush_tlb_mm_range+0x4a0/0x17a0 arch/x86/mm/tlb.c:1471
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:1041
page_mkclean_one+0x196/0x260 mm/rmap.c:1082
__rmap_walk_file+0x359/0x620 mm/rmap.c:2918
rmap_walk_file+0x174/0x1f0 mm/rmap.c:2951
rmap_walk mm/rmap.c:2962 [inline]
folio_mkclean+0x251/0x3f0 mm/rmap.c:1114
folio_clear_dirty_for_io+0x153/0x790 mm/page-writeback.c:2938
mpage_submit_folio+0x84/0x2d0 fs/ext4/inode.c:2061
mpage_map_and_submit_buffers+0x5c1/0xab0 fs/ext4/inode.c:2324
mpage_map_and_submit_extent fs/ext4/inode.c:2514 [inline]
ext4_do_writepages+0x2149/0x3cf0 fs/ext4/inode.c:2931
ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3025
do_writepages+0x27a/0x600 mm/page-writeback.c:2604
__writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1719
writeback_sb_inodes+0x60d/0xfa0 fs/fs-writeback.c:2015
__writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2086
wb_writeback+0x7f3/0xb70 fs/fs-writeback.c:2197
wb_check_old_data_flush fs/fs-writeback.c:2301 [inline]
wb_do_writeback fs/fs-writeback.c:2354 [inline]
wb_workfn+0x8ca/0xbe0 fs/fs-writeback.c:2382
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
process_scheduled_works kernel/workqueue.c:3346 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245