syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=f7e4/1/0x4000000000000000 softirq=117416/117419 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P19723/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=99521, q=230 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 19729 Comm: modprobe Not tainted 6.16.0-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kasan_check_range+0x1dd/0x2c0 mm/kasan/generic.c:189
Code: e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 12 41 80 3b 00 0f 85 b8 00 00 00 49 ff c3 49 ff cc 75 ee 5b 41 5c 41 5d 41 5e 41 5f 5d <e9> ce 6c 49 09 cc 45 84 ff 75 63 41 f7 c7 00 ff 00 00 75 5f 41 f7
RSP: 0018:ffffc90000a08b38 EFLAGS: 00000056
RAX: 00000000ffffff01 RBX: ffffffff99d102a8 RCX: ffffffff819edeb2
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff99d102a8
RBP: ffffc90000a08bf0 R08: ffffffff99d102ab R09: 1ffffffff33a2055
R10: dffffc0000000000 R11: fffffbfff33a2056 R12: ffffffff99d102b8
R13: ffffffff99d102b0 R14: 1ffffffff33a2057 R15: 1ffffffff33a2056
FS:  0000000000000000(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fba0005cf98 CR3: 000000005d4aa000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x112/0x290 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
 debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
 __run_hrtimer kernel/time/hrtimer.c:1729 [inline]
 __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5265
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 ff 1a d7 09 e8 da b7 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000beaf078 EFLAGS: 00000286
RAX: 5747a033c67b7d00 RBX: 0000000000000000 RCX: 5747a033c67b7d00
RDX: 0000000000000006 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40
RBP: ffffc9000beaf0d0 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e
R10: dffffc0000000000 R11: fffffbfff1f4167f R12: ffff8880309b1e00
R13: dffffc0000000000 R14: ffff8880314c5a00 R15: ffff8880b873a9d8
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x16b2/0x4c90 kernel/sched/core.c:6786
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6966
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6990
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
 debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836
 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
 __call_rcu_common kernel/rcu/tree.c:3079 [inline]
 call_rcu+0xaa/0x9c0 kernel/rcu/tree.c:3214
 slab_free_hook mm/slub.c:2345 [inline]
 slab_free mm/slub.c:4643 [inline]
 kmem_cache_free+0x309/0x400 mm/slub.c:4745
 remove_vma mm/vma.c:465 [inline]
 vms_complete_munmap_vmas+0x626/0x8a0 mm/vma.c:1288
 __mmap_complete mm/vma.c:2519 [inline]
 __mmap_region mm/vma.c:2630 [inline]
 mmap_region+0x161d/0x1f30 mm/vma.c:2692
 do_mmap+0xc45/0x10d0 mm/mmap.c:561
 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdcdc21b242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffe81c1b308 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fdcdbee6000 RCX: 00007fdcdc21b242
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007fdcdbee6000
RBP: 0000000000000812 R08: 0000000000000000 R09: 000000000005f000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffe81c1b3c8
R13: 00007fdcdbef26b0 R14: 00007ffe81c1b740 R15: 00000fffd0383664
 </TASK>
task:syz.3.5632      state:R  running task     stack:25032 pid:19723 tgid:19722 ppid:5842   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896
Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 fb 42 fe 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000da4f410 EFLAGS: 00000206
RAX: 45d985961c881700 RBX: 0000000000000202 RCX: 45d985961c881700
RDX: 0000000000000001 RSI: ffffffff8db6fcc6 RDI: ffffffff8be1ba40
RBP: ffff88802f5d8b18 R08: ffffc9000da4fa88 R09: 0000000000000000
R10: ffffc9000da4f598 R11: fffff52001b49eb5 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e13f0e0 R15: ffff88802f5d8000
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 kmem_cache_alloc_bulk_noprof+0x4e0/0x790 mm/slub.c:5374
 __io_alloc_req_refill+0x9d/0x280 io_uring/io_uring.c:972
 io_alloc_req io_uring/io_uring.h:447 [inline]
 io_submit_sqes+0xc31/0x1c50 io_uring/io_uring.c:2326
 __do_sys_io_uring_enter io_uring/io_uring.c:3404 [inline]
 __se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbedeb8eb69
RSP: 002b:00007fbedfa36038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fbededb5fa0 RCX: 00007fbedeb8eb69
RDX: 0000000000000000 RSI: 00000000000847ba RDI: 0000000000000004
RBP: 00007fbedec11df1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbededb5fa0 R15: 00007ffe205a1558
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g99521 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:27320 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1836 Comm: kworker/0:4 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events jump_label_update_timeout
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 80 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 6a 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 6a 0b
RSP: 0018:ffffc90004777780 EFLAGS: 00000293
RAX: ffffffff81b4bbb0 RBX: ffff8880b863b040 RCX: ffff888028d68000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900047778e0 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e
R10: dffffc0000000000 R11: fffffbfff1f4167f R12: 1ffff110170e7f2d
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873f968
FS:  0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2efe8e56c0 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000004 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
 smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 __static_key_slow_dec_cpuslocked+0xbb/0x110 kernel/jump_label.c:315
 __static_key_slow_dec kernel/jump_label.c:321 [inline]
 jump_label_update_timeout+0x1e/0x30 kernel/jump_label.c:329
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>