rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=9e64/1/0x4000000000000000 softirq=167517/167517 fqs=3
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5191/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=138629, q=242 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10373 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire+0xc4/0x340 kernel/locking/lockdep.c:5864
Code: 0f 85 eb 00 00 00 65 48 8b 04 25 08 c0 7d 92 83 b8 2c 0b 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 <4c> 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 fa 48 c7 c7 da b3 79 8d e8
RSP: 0018:ffffc90000007bc0 EFLAGS: 00000046
RAX: ffff88802528bd00 RBX: 0000000000000000 RCX: d08a9c2f49bca000
RDX: 0000000000000000 RSI: ffffffff8b5d5b4e RDI: 1ffff11005fd2258
RBP: ffffffff89713284 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff897131c0 R12: 0000000000000000
R13: ffff88802fe912c0 R14: 0000000000000000 R15: 0000000000000001
FS: 000055557cb92500(0000) GS:ffff888125e44000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dfa9bc0 CR3: 0000000057286000 CR4: 0000000000350ef0
Call Trace:
__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+0xc4/0xc90 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_lock_release include/linux/rcupdate.h:341 [inline]
RIP: 0010:rcu_read_unlock_sched include/linux/rcupdate.h:979 [inline]
RIP: 0010:pfn_valid+0x3aa/0x490 include/linux/mmzone.h:2193
Code: 8c fe 8d ff c6 05 87 c6 37 0d 01 48 c7 c7 00 5b 79 8b be d2 03 00 00 48 c7 c2 60 5c 79 8b e8 8d 0f 6b ff 48 c7 c7 a0 1a f4 8d <48> 89 de e8 0e f3 6a ff bf 01 00 00 00 e8 d4 59 5d ff 65 8b 1d 8d
RSP: 0018:ffffc90003cff350 EFLAGS: 00000293
RAX: ffffffff8233b229 RBX: ffffffff8233af9a RCX: ffff88802528bd00
RDX: 0000000000000000 RSI: ffffffff8bc01cc0 RDI: ffffffff8df41aa0
RBP: 0000000000000001 R08: ffffffff8233af9a R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: fffff94000435b99 R12: dffffc0000000000
R13: 0000000000000008 R14: 0000000000000001 R15: ffff88813fffa600
page_table_check_set+0x25/0x610 mm/page_table_check.c:105
page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
set_ptes include/linux/pgtable.h:292 [inline]
__copy_present_ptes mm/memory.c:1102 [inline]
copy_present_ptes mm/memory.c:1181 [inline]
copy_pte_range mm/memory.c:1304 [inline]
copy_pmd_range+0x4d02/0x7e00 mm/memory.c:1392
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0xb88/0x11d0 mm/memory.c:1535
dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1581
copy_process+0x165d/0x3950 kernel/fork.c:2221
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7106985e93
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc020c03a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7106985e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055557cb927d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000011f490 R15: 00007ffc020c0540
task:udevd state:R running task stack:22712 pid:5191 tgid:5191 ppid:1 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 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:unwind_next_frame+0xc9c/0x2390 arch/x86/kernel/unwind_orc.c:-1
Code: 4c 8b 6c 24 50 4c 8b 64 24 10 74 08 48 89 df e8 3a b8 b3 00 4c 89 23 ba 10 00 00 00 4c 89 ef 31 f6 e8 08 ba b3 00 48 8b 14 24 c5 04 00 00 4c 89 7c 24 28 48 89 5c 24 78 4d 8d 66 08 4d 89 e5
RSP: 0018:ffffc90003a27838 EFLAGS: 00000202
RAX: ffffc90003a27958 RBX: ffffc90003a27940 RCX: 0000000000000000
RDX: ffffffff90bb4d22 RSI: 0000000000000000 RDI: ffffc90003a27968
RBP: dffffc0000000000 R08: ffffc90003a27967 R09: ffffc90003a27958
R10: dffffc0000000000 R11: fffff52000744f2d R12: ffffc90003a27f48
R13: ffffc90003a27958 R14: ffffc90003a27908 R15: ffffc90003a27950
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
kvfree_call_rcu+0x11b/0x480 mm/slab_common.c:1994
kernfs_unlink_open_file+0x416/0x4c0 fs/kernfs/file.c:604
kernfs_fop_release+0x128/0x190 fs/kernfs/file.c:783
__fput+0x44c/0xa70 fs/file_table.c:468
fput_close_sync+0x113/0x220 fs/file_table.c:573
__do_sys_close fs/open.c:1573 [inline]
__se_sys_close fs/open.c:1558 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1558
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0ff6315a67
RSP: 002b:00007fff41866a48 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000556f15915280 RCX: 00007f0ff6315a67
RDX: 00007f0ff63efea0 RSI: 0000556f1592ca00 RDI: 000000000000000c
RBP: 00007f0ff63efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 0000556f0cb95100 R14: 00007fff41866db0 R15: 00007fff41866ca0
rcu: rcu_preempt kthread starved for 10496 jiffies! g138629 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 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:
CPU: 1 UID: 0 PID: 12943 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcd6/0x12b0 kernel/smp.c:877
Code: 83 e6 01 31 ff e8 1a 9a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 c5 95 0b 00 eb 38 f3 90 42 0f b6 04 2b 84 c0 <75> 11 41 f7 04 24 01 00 00 00 74 1e e8 a9 95 0b 00 eb e4 44 89 e1
RSP: 0018:ffffc9000e417560 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff110170c856d RCX: ffff88807b5c3d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000e4176e0 R08: ffffffff8f817977 R09: 1ffffffff1f02f2e
R10: dffffc0000000000 R11: fffffbfff1f02f2f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS: 0000555570913500(0000) GS:ffff888125f44000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000039a030 CR3: 000000008aae0000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472
dup_mmap+0x15fa/0x1b80 mm/mmap.c:1866
dup_mm kernel/fork.c:1529 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1581
copy_process+0x165d/0x3950 kernel/fork.c:2221
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone kernel/fork.c:2792 [inline]
__se_sys_clone kernel/fork.c:2776 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce71585e93
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffeca06fb18 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fce71585e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555709137d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000011fb7b R15: 00007ffeca06fcb0