rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10225/1:b..l..
rcu: (detected by 0, t=10502 jiffies, g=84725, q=1993 ncpus=1)
task:syz.8.1007 state:R running task stack:25576 pid:10225 tgid:10225 ppid:6829 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
preempt_schedule_common+0x7f/0xd0 kernel/sched/core.c:7561
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:201 [inline]
_raw_spin_unlock+0x41/0x50 kernel/locking/spinlock.c:213
spin_unlock include/linux/spinlock.h:401 [inline]
zap_pte_range mm/memory.c:2058 [inline]
zap_pmd_range mm/memory.c:2114 [inline]
zap_pud_range mm/memory.c:2142 [inline]
zap_p4d_range mm/memory.c:2163 [inline]
__zap_vma_range+0x40e1/0x4f70 mm/memory.c:2203
unmap_vmas+0x38b/0x550 mm/memory.c:2272
exit_mmap+0x293/0x9f0 mm/mmap.c:1315
__mmput+0x118/0x420 kernel/fork.c:1191
exit_mm+0x18e/0x240 kernel/exit.c:586
do_exit+0x6a8/0x2360 kernel/exit.c:967
do_group_exit+0x22d/0x2f0 kernel/exit.c:1123
get_signal+0x1216/0x12c0 kernel/signal.c:3112
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b7859f559
RSP: 002b:00007ffcbad7b5c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffff92 RBX: 000000000007953a RCX: 00007f4b7859f559
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4b78825fac
RBP: 0000000000000fd2 R08: 3fffffffffffffff R09: 0000000000000000
R10: 00007ffcbad7b6d0 R11: 0000000000000246 R12: 00007ffcbad7b6f0
R13: 00007f4b78825fac R14: 000000000007a50c R15: 00007ffcbad7b6d0
rcu: rcu_preempt kthread starved for 1365 jiffies! g84725 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5820 kernel/sched/core.c:7382
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline]
irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__timer_delete_sync+0x100/0x520 kernel/time/timer.c:1611
Code: 00 48 85 db 75 16 e8 ff 75 14 00 eb 15 e8 f8 75 14 00 e8 23 25 47 0a 48 85 db 74 ea e8 e9 75 14 00 fb 65 48 8b 1d 10 ff e8 12 <48> 89 de 48 81 e6 00 00 00 0f 31 ff e8 8f 7b 14 00 49 bf 00 00 00
RSP: 0018:ffffc90000157a98 EFLAGS: 00000293
RAX: ffffffff81b480f7 RBX: 8000000000000000 RCX: ffff88801f288000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000157bd0 R08: ffffffff917ca3bf R09: 1ffffffff22f9477
R10: dffffc0000000000 R11: fffffbfff22f9478 R12: ffffc90000157b00
R13: ffffc90000157b00 R14: 0000000000000000 R15: ffffffff81b48088
schedule_timeout+0x15a/0x2c0 kernel/time/sleep_timeout.c:100
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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:
CPU: 0 UID: 0 PID: 36 Comm: kcompactd0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221
Code: f7 e8 5d 40 a6 f5 f7 c3 00 02 00 00 74 05 e8 30 d7 d2 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 39 97 f5 65 48 8b 05 dc 10 9f 08 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc90000007b08 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000246 RCX: 8000000000000102
RDX: 0000000000000000 RSI: ffffffff8e493bea RDI: 0000000000000001
RBP: ffffc90000007e20 R08: ffffffff917ca3bf R09: 1ffffffff22f9477
R10: dffffc0000000000 R11: fffffbfff22f9478 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff88802a2ac000 R15: ffff88802a9a7410
FS: 0000000000000000(0000) GS:ffff888123a48000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f932a70b94d CR3: 0000000057556000 CR4: 0000000000350ef0
Call Trace:
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
dummy_timer+0x4948/0x4cc0 drivers/usb/gadget/udc/dummy_hcd.c:-1
__run_hrtimer kernel/time/hrtimer.c:2075 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2132
hrtimer_run_softirq+0x1e3/0x2e0 kernel/time/hrtimer.c:2149
handle_softirqs+0x265/0x8d0 kernel/softirq.c:669
__do_softirq kernel/softirq.c:703 [inline]
invoke_softirq kernel/softirq.c:542 [inline]
__irq_exit_rcu+0xc6/0x220 kernel/softirq.c:786
irq_exit_rcu+0x9/0x30 kernel/softirq.c:809
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__schedule+0x1828/0x5820 kernel/sched/core.c:7390
Code: 24 20 01 00 00 0e 36 e0 45 4a c7 04 2b 00 00 00 00 4a c7 44 2b 08 00 00 00 00 65 48 8b 05 18 dd a0 08 48 3b 84 24 a0 01 00 00 <0f> 85 47 08 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 da
RSP: 0018:ffffc90000ac77e0 EFLAGS: 00000246
RAX: dbb1da082b198100 RBX: 1ffff92000158f20 RCX: 8000000000000002
RDX: 0000000000000000 RSI: ffffffff8c6e7260 RDI: ffffffff8c6e7220
RBP: ffffc90000ac79d8 R08: ffffffff917ca3bf R09: 1ffffffff22f9477
R10: dffffc0000000000 R11: fffffbfff22f9478 R12: ffff888140ac8000
R13: dffffc0000000000 R14: ffff888023685dc0 R15: ffff8880b843c0d8
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
kcompactd+0x3f2/0x12a0 mm/compaction.c:3215
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245