rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7253
rcu: 	(detected by 0, t=10502 jiffies, g=22277, q=235 ncpus=2)
task:syz.1.494       state:R  running task     stack:26184 pid:7253  ppid:5787   flags:0x0000400a
Call Trace:
 <IRQ>
 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:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:handle_softirqs+0x1b0/0x820 kernel/softirq.c:566
Code: 89 64 24 2c 0f b7 db 48 c7 c7 a0 b2 a9 8a e8 77 99 1b 09 65 66 c7 05 1d 25 b2 7e 00 00 e8 98 63 3a 00 fb 49 c7 c6 c0 a0 a0 8c <89> 5c 24 34 b8 ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 84
RSP: 0018:ffffc90000007e40 EFLAGS: 00000286
RAX: 8d0925f4a90d5800 RBX: 0000000000000200 RCX: 8d0925f4a90d5800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6700
RBP: ffffc90000007f50 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 000000000000000a
R13: 0000000000000000 R14: ffffffff8ca0a0c0 R15: ffff88807bb19e00
 __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
 </IRQ>
 <TASK>
 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 b9 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:ffffc90004fbfc00 EFLAGS: 00000206
RAX: 8d0925f4a90d5800 RBX: 1ffff920009f7f88 RCX: 8d0925f4a90d5800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6700
RBP: ffffc90004fbfcf0 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: 0033:0x7f575198e9a9
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:00007ffddb4618c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000002ae6f RCX: 00007f575198e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5751bb7ba0 R08: 0000000000000001 R09: 0000000edb461bbf
R10: 00007f5751600000 R11: 0000000000000246 R12: 00007f5751bb5fac
R13: 00007f5751bb5fa0 R14: ffffffffffffffff R15: 00007ffddb4619e0
 </TASK>
rcu: rcu_preempt kthread starved for 10497 jiffies! g22277 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:26728 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 7253 Comm: syz.1.494 Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:handle_softirqs+0x1b0/0x820 kernel/softirq.c:566
Code: 89 64 24 2c 0f b7 db 48 c7 c7 a0 b2 a9 8a e8 77 99 1b 09 65 66 c7 05 1d 25 b2 7e 00 00 e8 98 63 3a 00 fb 49 c7 c6 c0 a0 a0 8c <89> 5c 24 34 b8 ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 84
RSP: 0018:ffffc90000007e40 EFLAGS: 00000286
RAX: 8d0925f4a90d5800 RBX: 0000000000000200 RCX: 8d0925f4a90d5800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6700
RBP: ffffc90000007f50 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: 000000000000000a
R13: 0000000000000000 R14: ffffffff8ca0a0c0 R15: ffff88807bb19e00
FS:  000055556029d500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c291f46 CR3: 0000000054865000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __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
 </IRQ>
 <TASK>
 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 b9 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:ffffc90004fbfc00 EFLAGS: 00000206
RAX: 8d0925f4a90d5800 RBX: 1ffff920009f7f88 RCX: 8d0925f4a90d5800
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6700
RBP: ffffc90004fbfcf0 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: 0033:0x7f575198e9a9
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:00007ffddb4618c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000002ae6f RCX: 00007f575198e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5751bb7ba0 R08: 0000000000000001 R09: 0000000edb461bbf
R10: 00007f5751600000 R11: 0000000000000246 R12: 00007f5751bb5fac
R13: 00007f5751bb5fa0 R14: ffffffffffffffff R15: 00007ffddb4619e0
 </TASK>