rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29422 P29434/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=252325, q=57 ncpus=2)
task:syz.4.9654 state:R running task stack:25960 pid:29434 ppid:13421 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1522 [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+0x236f/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
copy_process+0x294b/0x3d70 kernel/fork.c:2765
kernel_clone+0x21b/0x840 kernel/fork.c:2914
__do_sys_clone kernel/fork.c:3057 [inline]
__se_sys_clone kernel/fork.c:3041 [inline]
__x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6c9598ebe9
RSP: 002b:00007f6c968acfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f6c95bb5fa0 RCX: 00007f6c9598ebe9
RDX: ffffffff81000000 RSI: 0000000000000000 RDI: 000000000a089400
RBP: 00007f6c95a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f6c95bb6038 R14: 00007f6c95bb5fa0 R15: 00007ffceb29cfa8
task:syz.0.9650 state:R running task stack:27016 pid:29422 ppid:13235 flags:0x0000400a
Call Trace:
sched_show_task+0x481/0x5a0 kernel/sched/core.c:9179
rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:261 [inline]
print_other_cpu_stall+0xfa7/0x1340 kernel/rcu/tree_stall.h:637
check_cpu_stall kernel/rcu/tree_stall.h:809 [inline]
rcu_pending kernel/rcu/tree.c:3950 [inline]
rcu_sched_clock_irq+0x87c/0x1220 kernel/rcu/tree.c:2295
update_process_times+0x147/0x1b0 kernel/time/timer.c:2071
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x3a2/0x580 kernel/time/tick-sched.c:1492
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x4df/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+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900001f0900 EFLAGS: 00000206
RAX: ccf731450f64b800 RBX: 1ffff9200003e128 RCX: ccf731450f64b800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc900001f0a00 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd354d8
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2323 [inline]
bpf_trace_run1+0x256/0x3b0 kernel/trace/bpf_trace.c:2360
__bpf_trace_rcu_utilization+0xa2/0xe0 include/trace/events/rcu.h:27
trace_rcu_utilization+0x179/0x1a0 include/trace/events/rcu.h:27
rcu_core+0x1341/0x1720 kernel/rcu/tree.c:2475
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0xa1/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc9000c197c00 EFLAGS: 00000206
RAX: ccf731450f64b800 RBX: 1ffff92001832f88 RCX: ccf731450f64b800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc9000c197cf0 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd354d8
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock+0x85/0xa0 include/linux/rcupdate.h:818
dput+0xe6/0x1e0 fs/dcache.c:911
__fput+0x5e5/0x970 fs/file_table.c:392
task_work_run+0x1ce/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
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: 0033:0x7fbef838ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef91ef9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fbef85b7da0 RCX: 00007fbef838ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fbef85b7da0 R08: 0000000000018b34 R09: 0000000ef91efccf
R10: 00000000005e1be8 R11: 0000000000000246 R12: 0000000000172a94
R13: 00007ffef91efad0 R14: ffffffffffffffff R15: 00007ffef91efaf0
rcu: rcu_preempt kthread starved for 10597 jiffies! g252325 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:26664 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14d2/0x44d0 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: 1 PID: 29422 Comm: syz.0.9650 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900001f0900 EFLAGS: 00000206
RAX: ccf731450f64b800 RBX: 1ffff9200003e128 RCX: ccf731450f64b800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc900001f0a00 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd354d8
FS: 0000555583f8b500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33b1dff8 CR3: 000000001e375000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2323 [inline]
bpf_trace_run1+0x256/0x3b0 kernel/trace/bpf_trace.c:2360
__bpf_trace_rcu_utilization+0xa2/0xe0 include/trace/events/rcu.h:27
trace_rcu_utilization+0x179/0x1a0 include/trace/events/rcu.h:27
rcu_core+0x1341/0x1720 kernel/rcu/tree.c:2475
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0xa1/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc9000c197c00 EFLAGS: 00000206
RAX: ccf731450f64b800 RBX: 1ffff92001832f88 RCX: ccf731450f64b800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc9000c197cf0 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd354d8
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock+0x85/0xa0 include/linux/rcupdate.h:818
dput+0xe6/0x1e0 fs/dcache.c:911
__fput+0x5e5/0x970 fs/file_table.c:392
task_work_run+0x1ce/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
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: 0033:0x7fbef838ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef91ef9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fbef85b7da0 RCX: 00007fbef838ebe9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fbef85b7da0 R08: 0000000000018b34 R09: 0000000ef91efccf
R10: 00000000005e1be8 R11: 0000000000000246 R12: 0000000000172a94
R13: 00007ffef91efad0 R14: ffffffffffffffff R15: 00007ffef91efaf0