rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22368/3:b..l P22359/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=137801, q=956 ncpus=2)
task:syz.3.4121 state:R running task stack:26840 pid:22359 tgid:22350 ppid:17172 task_flags:0x40054c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5df0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: b2 38 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 92 06 10 0f 0f 82 74 02 00 00 8b 35 7a 38 10 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 e9 b1 38 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90011e76de8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e5c1060 RCX: 00000000bc0f0e5c
RDX: 0000000000000000 RSI: ffffffff8ddf01fe RDI: ffffffff8c15fc80
RBP: 0000000000000002 R08: 35f63e442a7e7453 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
free_unref_folios+0xa65/0x1800 mm/page_alloc.c:2763
folios_put_refs+0x56f/0x740 mm/swap.c:992
free_pages_and_swap_cache+0x245/0x4a0 mm/swap_state.c:264
__tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0xe9/0x5a0 mm/mmu_gather.c:404
zap_pte_range mm/memory.c:1792 [inline]
zap_pmd_range mm/memory.c:1845 [inline]
zap_pud_range mm/memory.c:1874 [inline]
zap_p4d_range mm/memory.c:1895 [inline]
unmap_page_range+0x2040/0x4350 mm/memory.c:1916
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1959
unmap_vmas+0x218/0x470 mm/memory.c:2003
exit_mmap+0x1b9/0xb90 mm/mmap.c:1284
__mmput+0x12a/0x410 kernel/fork.c:1125
mmput+0x62/0x70 kernel/fork.c:1148
exit_mm kernel/exit.c:581 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:952
do_group_exit+0xd3/0x2a0 kernel/exit.c:1105
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:224 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8533d8eb69
RSP: 002b:00007f8534b560e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f8533fb6168 RCX: 00007f8533d8eb69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8533fb6168
RBP: 00007f8533fb6160 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8533fb616c
R13: 0000000000000000 R14: 00007ffe3e32a6b0 R15: 00007ffe3e32a798
task:udevd state:R running task stack:28408 pid:22368 tgid:22368 ppid:5197 task_flags:0x400040 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5df0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
filemap_map_pages+0xe2e/0x1680 mm/filemap.c:3757
do_fault_around mm/memory.c:5566 [inline]
do_read_fault mm/memory.c:5599 [inline]
do_fault mm/memory.c:5742 [inline]
do_pte_missing mm/memory.c:4269 [inline]
handle_pte_fault mm/memory.c:6087 [inline]
__handle_mm_fault+0x3b06/0x5390 mm/memory.c:6230
handle_mm_fault+0x589/0xd10 mm/memory.c:6399
do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f7052bfa140
RSP: 002b:00007ffdb8ddf1b8 EFLAGS: 00010282
RAX: 00000000fffffff7 RBX: 000055bc64dcf7a0 RCX: 000000000000006d
RDX: 0000000000000008 RSI: 000055bc2ae14ab2 RDI: 000055bc64db56f4
RBP: 0000000000000000 R08: 000055bc2ae14c29 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055bc64db56f4
R13: 000055bc2ae14c29 R14: 000055bc2ae17ca4 R15: 000055bc2ae17bcc
rcu: rcu_preempt kthread starved for 10542 jiffies! g137801 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5df0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
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: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller-08685-g260f6f4fda93 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: bc 65 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 82 1d 00 fb f4 4c 0b 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c6
RAX: 0000000008503efd RBX: 0000000000000000 RCX: ffffffff8b8c8c69
RDX: 0000000000000000 RSI: ffffffff8de155b0 RDI: ffffffff8c15fc80
RBP: fffffbfff1c52ef0 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e297780 R14: ffffffff90a7c490 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124719000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbba1ae635a CR3: 000000007e5bc000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
rest_init+0x16b/0x2b0 init/main.c:744
start_kernel+0x3ee/0x4d0 init/main.c:1097
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x148