rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7649/1:b..l P7650/1:b..l P7678/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=25161, q=581 ncpus=2)
task:syz.4.338 state:R running task stack:25688 pid:7678 tgid:7678 ppid:5816 task_flags:0x40044c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:392 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x38be/0x4170 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x169/0x230 kernel/exit.c:581
do_exit+0x627/0x22f0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feae41c3e89
RSP: 002b:00007ffd399408c8 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: 00000000000000ec RBX: 00007feae41462a0 RCX: 00007feae41c3e89
RDX: 00007feae41462a0 RSI: 0000000000000058 RDI: 00007ffd39940910
RBP: 00007feae50906c0 R08: 00007feae50906c0 R09: 00007ffd399409f7
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000006e R14: 00007ffd39940910 R15: 00007ffd399409f8
task:syz.5.336 state:R running task stack:26224 pid:7650 tgid:7648 ppid:7123 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0x127/0x23d0 arch/x86/kernel/unwind_orc.c:498
Code: 48 c7 c2 40 91 88 8b e8 d7 3f 2a 00 4c 89 6c 24 78 48 89 5c 24 70 4d 8d 6e 50 4c 89 e8 48 c1 e8 03 48 89 44 24 38 80 3c 28 00 <74> 08 4c 89 ef e8 8f 8d b3 00 49 8b 5d 00 48 85 db 74 23 48 81 c3
RSP: 0018:ffffc9000b25f4d8 EFLAGS: 00000246
RAX: 1ffff9200164bebf RBX: ffffffff848455d8 RCX: 0000000080000001
RDX: 00000000ba471a7c RSI: ffffffff8be08c40 RDI: ffffffff8be08c00
RBP: dffffc0000000000 R08: ffffffff8173fd75 R09: ffffffff8e13efa0
R10: ffffc9000b25f5f8 R11: ffffffff81acb2b0 R12: 1ffff9200164beb5
R13: ffffc9000b25f5f8 R14: ffffc9000b25f5a8 R15: ffffffff8173fd75
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2517 [inline]
slab_free mm/slub.c:6690 [inline]
kmem_cache_free+0x475/0x620 mm/slub.c:6801
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2804
io_queue_deferred+0x81/0x400 io_uring/io_uring.c:509
__io_submit_flush_completions+0xea5/0xfc0 io_uring/io_uring.c:1531
io_submit_flush_completions io_uring/io_uring.h:238 [inline]
__io_run_local_work+0x5cc/0x920 io_uring/io_uring.c:1374
__do_sys_io_uring_enter io_uring/io_uring.c:3275 [inline]
__se_sys_io_uring_enter+0x1378/0x2b60 io_uring/io_uring.c:3201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f342ed8f749
RSP: 002b:00007f342fbef038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f342efe6090 RCX: 00007f342ed8f749
RDX: 0000000000006933 RSI: 00000000000008ae RDI: 0000000000000000
RBP: 00007f342ee13f91 R08: 0000000000000000 R09: 000000000000effd
R10: 0000000000000017 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f342efe6128 R14: 00007f342efe6090 R15: 00007ffcc888dcf8
task:syz.5.336 state:R running task stack:25336 pid:7649 tgid:7648 ppid:7123 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7171
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753
rcu_read_lock include/linux/rcupdate.h:851 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd4/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
slab_free_hook mm/slub.c:2517 [inline]
slab_free mm/slub.c:6690 [inline]
kmem_cache_free+0x475/0x620 mm/slub.c:6801
__io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2804
io_queue_deferred+0x81/0x400 io_uring/io_uring.c:509
__io_submit_flush_completions+0xea5/0xfc0 io_uring/io_uring.c:1531
io_submit_flush_completions io_uring/io_uring.h:238 [inline]
__io_run_local_work+0x5cc/0x920 io_uring/io_uring.c:1374
__do_sys_io_uring_enter io_uring/io_uring.c:3275 [inline]
__se_sys_io_uring_enter+0x1378/0x2b60 io_uring/io_uring.c:3201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f342ed8f749
RSP: 002b:00007f342fc10038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f342efe5fa0 RCX: 00007f342ed8f749
RDX: 0000000000006933 RSI: 00000000000008ae RDI: 0000000000000000
RBP: 00007f342ee13f91 R08: 0000000000000000 R09: 000000000000effd
R10: 0000000000000017 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f342efe6038 R14: 00007f342efe5fa0 R15: 00007ffcc888dcf8
rcu: rcu_preempt kthread starved for 10612 jiffies! g25161 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:27640 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 be 2a 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2
RAX: 000000000026bef7 RBX: ffffffff8197161e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d9a0b7f RDI: ffffffff8be08c60
RBP: ffffc90000197f10 R08: ffff8880b873375b R09: 1ffff110170e66eb
R10: dffffc0000000000 R11: ffffed10170e66ec R12: ffffffff8fa25d70
R13: 1ffff11003ad4b58 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d07000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3d45ea CR3: 000000002b07a000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147