rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15037/2:b..l
rcu: (detected by 0, t=10502 jiffies, g=108241, q=533 ncpus=2)
task:syz.1.1915 state:R running task stack:25712 pid:15037 tgid:15036 ppid:14328 task_flags:0x40044c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__rcu_read_unlock+0x61/0xe0 kernel/rcu/tree_plugin.h:441
Code: ff 0b 75 1d 4c 8d b7 88 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 66 41 83 3e 00 75 27 43 0f b6 04 3c 84 c0 75 41 <8b> 03 3d 00 00 00 40 73 0f 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc
RSP: 0018:ffffc90005c2f370 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888024a80484 RCX: 33334fe5caedaa00
RDX: 0000000000000004 RSI: ffffffff8cfd6aba RDI: ffff888024a80000
RBP: ffffc90005c2f630 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1003c19988 R12: 1ffff11004950090
R13: dffffc0000000000 R14: ffff888058799680 R15: dffffc0000000000
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1626 [inline]
zap_present_ptes mm/memory.c:1708 [inline]
do_zap_pte_range mm/memory.c:1810 [inline]
zap_pte_range mm/memory.c:1854 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x2f39/0x3ce0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0xcb/0x3d0 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x125d/0x1310 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd0fa36f749
RSP: 002b:00007fd0f85d60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd0fa5c5fa8 RCX: 00007fd0fa36f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd0fa5c5fa8
RBP: 00007fd0fa5c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0fa5c6038 R14: 00007ffc49d4d500 R15: 00007ffc49d4d5e8
rcu: rcu_preempt kthread starved for 10433 jiffies! g108241 f0x0 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:26936 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1480/0x50a0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 03 ca 03 00 cc cc cc 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 c3 96 15 00 f3 0f 1e fa fb f4 d8 c9 03 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900001d7de0 EFLAGS: 000002c2
RAX: 9222c7a6ed1e0900 RBX: ffffffff819663da RCX: 9222c7a6ed1e0900
RDX: 0000000000000001 RSI: ffffffff8ce00c34 RDI: ffffffff8b3efa60
RBP: ffffc900001d7f10 R08: ffff8880b8933c5b R09: 1ffff1101712678b
R10: dffffc0000000000 R11: ffffed101712678c R12: ffffffff8eda9670
R13: 1ffff11003757b58 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126e12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005649266c20a8 CR3: 0000000030178000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_lockdep_rcu_enabled+0x6/0x40 kernel/rcu/update.c:320
Code: 04 48 c7 c6 07 ea de 8c 67 48 0f b9 3a 90 eb ca cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 <83> 3d 67 cf 07 04 00 74 1e 83 3d 4a de 07 04 00 74 15 65 48 8b 0c
RSP: 0018:ffffc900001573d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff9200002ae84 RCX: 9f5e7cffa5d09c00
RDX: 0000000000000200 RSI: 0000000000000030 RDI: ffffffff8aeb3ca0
RBP: ffffc900001574f0 R08: ffffffff867b6189 R09: ffff88803115d510
R10: 0000000000000100 R11: 00000000fffffffe R12: ffff8880328abdc0
R13: dffffc0000000000 R14: ffff88803115d4b8 R15: ffff88801b6ddf44
FS: 0000000000000000(0000) GS:ffff888126d12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fad92f324c0 CR3: 000000009970a000 CR4: 00000000003526f0
Call Trace:
__might_resched+0x91/0x5d0 kernel/sched/core.c:8789
__rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline]
rt_spin_lock+0xc7/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
usb_anchor_urb+0x29/0x200 drivers/usb/core/urb.c:131
ath9k_hif_usb_reg_in_cb+0x4c8/0x6f0 drivers/net/wireless/ath/ath9k/hif_usb.c:789
__usb_hcd_giveback_urb+0x3b4/0x5e0 drivers/usb/core/hcd.c:1661
dummy_timer+0x8a0/0x46f0 drivers/usb/gadget/udc/dummy_hcd.c:1995
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x542/0xd00 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858
handle_softirqs+0x226/0x6d0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246