rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (3 ticks this GP) idle=4c2c/1/0x4000000000000000 softirq=16854/16854 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6124/1:b..l
rcu: (detected by 0, t=10587 jiffies, g=10993, q=667 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6131 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_is_held kernel/locking/lockdep.c:5601 [inline]
RIP: 0010:lock_is_held_type+0xb0/0x150 kernel/locking/lockdep.c:5940
Code: 00 41 83 c7 01 45 3b bc 24 28 0b 00 00 0f 8d 80 00 00 00 49 63 c7 48 89 ee 48 8d 04 80 49 8d 5c c5 00 48 89 df e8 80 fe ff ff <85> c0 74 d3 41 bd 01 00 00 00 41 83 fe ff 74 13 31 c0 f6 43 22 03
RSP: 0000:ffffc90000a08d50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888027d68b80 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff88807e185300 RDI: ffff888027d68b80
RBP: ffff88807e185300 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888027d68000
R13: ffff888027d68b30 R14: 00000000ffffffff R15: 0000000000000002
FS: 00007f189d7bc880(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559d60661fe8 CR3: 000000002232f000 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:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfb/0x1600 kernel/smp.c:877
Code: ed 74 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 b5 0c 0c 00 90 41 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43
RSP: 0000:ffffc90002f07898 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8442840 RCX: ffffffff81b0db51
RDX: ffff888027d68000 RSI: ffffffff81b0db2b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffed1017088509 R14: 0000000000000001 R15: 0000000000000000
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
wp_page_copy mm/memory.c:3746 [inline]
do_wp_page+0x1774/0x52b0 mm/memory.c:4141
handle_pte_fault mm/memory.c:6211 [inline]
__handle_mm_fault+0x1ae3/0x2aa0 mm/memory.c:6336
handle_mm_fault+0x589/0xd10 mm/memory.c:6505
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+0x64/0xc0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f189d0b5db7
Code: 00 00 00 41 55 48 89 d0 49 89 fd 41 54 49 89 f4 53 4c 89 c3 48 83 ec 10 48 39 4f 60 0f 84 c1 00 00 00 42 f6 44 01 08 01 74 59 <48> 83 61 08 fe 48 3d ff 03 00 00 76 69 49 8b 55 70 49 8d 75 60 48
RSP: 002b:00007ffc9a01a550 EFLAGS: 00010202
RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 0000559d60661fe0
RDX: 0000000000006010 RSI: 0000559d6065bfd0 RDI: 00007f189d1f1ac0
RBP: 00007f189d1f1ac0 R08: 00000000000001f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000559d6065bfd0
R13: 00007f189d1f1ac0 R14: 00000000000001f0 R15: 00007f189d1f1ac0
task:syz.2.26 state:R running task stack:27656 pid:6124 tgid:6124 ppid:5957 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113
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]
zap_pte_range mm/memory.c:1885 [inline]
zap_pmd_range mm/memory.c:1947 [inline]
zap_pud_range mm/memory.c:1976 [inline]
zap_p4d_range mm/memory.c:1997 [inline]
unmap_page_range+0x214f/0x41b0 mm/memory.c:2018
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:2061
unmap_vmas+0x218/0x470 mm/memory.c:2105
exit_mmap+0x1b2/0xb90 mm/mmap.c:1280
__mmput+0x12a/0x410 kernel/fork.c:1133
mmput+0x62/0x70 kernel/fork.c:1156
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:954
do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [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+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff6eeb8f749
RSP: 002b:00007fff36211508 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ff6eede7da0 RCX: 00007ff6eeb8f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007ff6eede7da0 R08: 0000000000000000 R09: 00000004362117ff
R10: 000000000003fdc0 R11: 0000000000000246 R12: 0000000000036751
R13: 00007fff36211600 R14: ffffffffffffffff R15: 00007fff36211620
rcu: rcu_preempt kthread timer wakeup didn't happen for 10586 jiffies! g10993 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=8591
rcu: rcu_preempt kthread starved for 10587 jiffies! g10993 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28696 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