rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=c96c/1/0x4000000000000000 softirq=14867/14872 fqs=3
rcu: (detected by 0, t=10502 jiffies, g=15781, q=321 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6528 Comm: syz.1.228 Not tainted 6.6.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__rcu_read_unlock+0x60/0xd0 kernel/rcu/tree_plugin.h:429
Code: ff 0b 75 1d 4c 8d b7 40 04 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 75 5f 41 83 3e 00 75 20 43 0f b6 04 3c 84 c0 75 3a <8b> 03 3d 00 00 00 40 73 0a 5b 41 5c 41 5d 41 5e 41 5f c3 0f 0b eb
RSP: 0018:ffffc900001f0c40 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88802c38a23c RCX: ffff88802c389e00
RDX: 0000000000010000 RSI: ffffffff8afc6ce0 RDI: ffff88802c389e00
RBP: 0000000000000001 R08: ffff888076fbc15f R09: 1ffff1100edf782b
R10: dffffc0000000000 R11: ffffed100edf782c R12: 1ffff11005871447
R13: ffff888076fbc000 R14: 18575c6555d717d0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d91effc CR3: 000000000cb30000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
advance_sched+0xb1a/0xc80 net/sched/sch_taprio.c:998
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90004c5f400 EFLAGS: 00000206
RAX: dee656a1ec677400 RBX: ffff88802c389e00 RCX: dee656a1ec677400
RDX: 0000000000000000 RSI: ffffffff8aaac440 RDI: ffffffff8afc6d00
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff21b4aa4
R10: dffffc0000000000 R11: fffffbfff21b4aa5 R12: 0000000000000001
R13: 0000000000000246 R14: ffffffff8cd2f760 R15: ffff88802c38a908
lookup_page_ext mm/page_ext.c:240 [inline]
page_ext_get+0x193/0x2b0 mm/page_ext.c:509
page_table_check_clear+0x4a/0x6a0 mm/page_table_check.c:74
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
zap_pte_range mm/memory.c:1428 [inline]
zap_pmd_range mm/memory.c:1570 [inline]
zap_pud_range mm/memory.c:1599 [inline]
zap_p4d_range mm/memory.c:1620 [inline]
unmap_page_range+0x1ad1/0x2fe0 mm/memory.c:1641
unmap_vmas+0x25e/0x3a0 mm/memory.c:1731
exit_mmap+0x200/0xb50 mm/mmap.c:3298
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa3f2f8e929
Code: Unable to access opcode bytes at 0x7fa3f2f8e8ff.
RSP: 002b:00007fa3f3d620e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fa3f31b5fa8 RCX: 00007fa3f2f8e929
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fa3f31b5fac
RBP: 00007fa3f31b5fa0 R08: 0000000000745d1e R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fa3f31b5fac
R13: 0000000000000000 R14: 00007ffc2708d3c0 R15: 00007ffc2708d4a8
rcu: rcu_preempt kthread starved for 10496 jiffies! g15781 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:27448 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 1121 Comm: kworker/u4:6 Not tainted 6.6.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 2a e7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 65 e3 0a 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 49 e3
RSP: 0018:ffffc9000476f780 EFLAGS: 00000293
RAX: ffffffff817ab317 RBX: 1ffff110171e82f5 RCX: ffff88802350da00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000476f900 R08: ffffffff90da5527 R09: 1ffffffff21b4aa4
R10: dffffc0000000000 R11: fffffbfff21b4aa5 R12: ffff8880b8f417a8
R13: dffffc0000000000 R14: ffff8880b8e3d588 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1528fb5fac CR3: 000000000cb30000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293