rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P29/2:b..l P16/5:b..l P5807/5:b..l P8912/1:b..l P5786/3:b..l
rcu: (detected by 1, t=10502 jiffies, g=35141, q=514 ncpus=2)
task:syz-executor state:R running task stack:21256 pid:5786 tgid:5786 ppid:5785 task_flags:0x400100 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
class_preempt_destructor include/linux/preempt.h:470 [inline]
try_to_wake_up+0x82b/0x12b0 kernel/sched/core.c:4300
signal_wake_up_state+0xb5/0x120 kernel/signal.c:734
signal_wake_up include/linux/sched/signal.h:450 [inline]
complete_signal+0xa23/0xbc0 kernel/signal.c:1023
__send_signal_locked+0xbb3/0xec0 kernel/signal.c:1153
do_send_sig_info kernel/signal.c:1269 [inline]
group_send_sig_info+0x1f4/0x250 kernel/signal.c:1419
kill_pid_info_type+0xf8/0x1f0 kernel/signal.c:1459
kill_pid_info kernel/signal.c:1473 [inline]
kill_proc_info+0xd9/0x180 kernel/signal.c:1480
kill_something_info kernel/signal.c:1577 [inline]
__do_sys_kill kernel/signal.c:3955 [inline]
__se_sys_kill+0xc4/0x450 kernel/signal.c:3949
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19872fba37
RSP: 002b:00007ffe172867c8 EFLAGS: 00000202 ORIG_RAX: 000000000000003e
RAX: ffffffffffffffda RBX: 00007ffe17286d10 RCX: 00007f19872fba37
RDX: 0000000000000003 RSI: 0000000000000009 RDI: 00000000000020a4
RBP: 00005555559adb10 R08: 00005555559b2500 R09: 00005555559b2528
R10: c4020e8dd97fbbba R11: 0000000000000202 R12: 00007ffe172867dc
R13: 00005555559ac4c0 R14: 00005555559b2500 R15: 00007ffe17286870
task:syz.2.727 state:R running task stack:28072 pid:8912 tgid:8906 ppid:5799 task_flags:0x400040 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893
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 db af 06 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:ffffc90004ab75f0 EFLAGS: 00000206
RAX: f1d4b4f93ecdcc00 RBX: 0000000000000206 RCX: f1d4b4f93ecdcc00
RDX: 0000000000000000 RSI: ffffffff8cf65609 RDI: ffffffff8b3ddfe0
RBP: ffff88802d338b88 R08: 0000000000000000 R09: ffffffff8ac2db41
R10: 0000000000000000 R11: ffffed1007a97e1d R12: 0000000000000002
R13: 0000000000000002 R14: ffff888037bf9798 R15: ffff88802d338000
rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
__skb_try_recv_datagram+0xa9/0x1b0 net/core/datagram.c:267
__unix_dgram_recvmsg+0x2d4/0xd60 net/unix/af_unix.c:2601
sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1078
____sys_recvmsg+0x3ab/0x470 net/socket.c:2848
___sys_recvmsg+0x1b5/0x510 net/socket.c:2892
do_recvmmsg+0x30d/0x770 net/socket.c:2987
__sys_recvmmsg net/socket.c:3061 [inline]
__do_sys_recvmmsg net/socket.c:3084 [inline]
__se_sys_recvmmsg net/socket.c:3077 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe355eff749
RSP: 002b:00007fe354145038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fe356156090 RCX: 00007fe355eff749
RDX: 000000000400034f RSI: 0000200000000480 RDI: 0000000000000003
RBP: 00007fe355f83f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe356156128 R14: 00007fe356156090 R15: 00007ffdbd9eeac8
task:syz-executor state:R running task stack:21512 pid:5807 tgid:5807 ppid:5796 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d c4 28 3b 0b 48 89 de 5b e9 73 c2 56 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 a0 a2 91 65 8b 35 c8 f2
RSP: 0018:ffffc90004bc73a0 EFLAGS: 00000202
RAX: 0000000000007fb3 RBX: 0000000000057fb3 RCX: ffff888025648000
RDX: 0000000000000000 RSI: 0000000000007fb3 RDI: 0000000000000000
RBP: ffff88801be7e7a0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10037cfcfe R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000057fb2 R15: 0000000000000001
page_ext_next include/linux/page_ext.h:108 [inline]
page_ext_iter_next include/linux/page_ext.h:156 [inline]
page_table_check_set+0x3ec/0x730 mm/page_table_check.c:113
page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
set_ptes include/linux/pgtable.h:292 [inline]
__copy_present_ptes mm/memory.c:1101 [inline]
copy_present_ptes mm/memory.c:1180 [inline]
copy_pte_range mm/memory.c:1303 [inline]
copy_pmd_range+0x4790/0x7950 mm/memory.c:1390
copy_pud_range mm/memory.c:1427 [inline]
copy_p4d_range mm/memory.c:1451 [inline]
copy_page_range+0xaff/0x1170 mm/memory.c:1539
dup_mmap+0xf5b/0x1ae0 mm/mmap.c:1834
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1704/0x3ae0 kernel/fork.c:2181
kernel_clone+0x224/0x7c0 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac6ccb5e93
RSP: 002b:00007ffcbf03da88 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fac6ccb5e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556e9817d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000006dace R15: 00007ffcbf03dc20
task:ktimers/0 state:R running task stack:21336 pid:16 tgid:16 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
rt_mutex_wake_up_q kernel/locking/rtmutex.c:575 [inline]
rt_mutex_slowunlock+0x668/0x8a0 kernel/locking/rtmutex.c:1469
spin_unlock include/linux/spinlock_rt.h:105 [inline]
___slab_alloc+0x87a/0x1400 mm/slub.c:4554
__slab_alloc+0xc6/0x1f0 mm/slub.c:4778
__slab_alloc_node mm/slub.c:4854 [inline]
slab_alloc_node mm/slub.c:5276 [inline]
kmem_cache_alloc_noprof+0xec/0x6b0 mm/slub.c:5295
skb_clone+0x212/0x3a0 net/core/skbuff.c:2050
hsr_forward_do net/hsr/hsr_forward.c:-1 [inline]
hsr_forward_skb+0x1013/0x2860 net/hsr/hsr_forward.c:741
send_hsr_supervision_frame+0x74d/0xce0 net/hsr/hsr_device.c:364
hsr_announce+0x1d5/0x360 net/hsr/hsr_device.c:421
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x648/0x970 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
handle_softirqs+0x22f/0x710 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
task:ktimers/1 state:R running task stack:21976 pid:29 tgid:29 ppid:2 task_flags:0x4208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
rt_mutex_wake_up_q kernel/locking/rtmutex.c:575 [inline]
rt_mutex_slowunlock+0x668/0x8a0 kernel/locking/rtmutex.c:1469
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
class_spinlock_irqsave_destructor include/linux/spinlock.h:585 [inline]
snd_seq_timer_interrupt+0x34f/0x470 sound/core/seq/seq_timer.c:131
snd_timer_process_callbacks+0x225/0x2f0 sound/core/timer.c:785
snd_timer_interrupt+0xecb/0x10c0 sound/core/timer.c:901
snd_hrtimer_callback+0x213/0x3a0 sound/core/hrtimer.c:51
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x552/0xd40 kernel/time/hrtimer.c:1841
hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858
handle_softirqs+0x22f/0x710 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g35141 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=21476
rcu: rcu_preempt kthread starved for 10502 jiffies! g35141 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27240 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(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 63 a7 27 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:ffffffff8d207d80 EFLAGS: 000002c2
RAX: dcb8d21bb69e7500 RBX: ffffffff81953c47 RCX: dcb8d21bb69e7500
RDX: 0000000000000001 RSI: ffffffff8cd8e759 RDI: ffffffff8b3ddfe0
RBP: ffffffff8d207ea8 R08: ffff8880b88334db R09: 1ffff1101710669b
R10: dffffc0000000000 R11: ffffed101710669c R12: ffffffff8ed64270
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1a60640
FS: 0000000000000000(0000) GS:ffff888126df6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd1dfda59a0 CR3: 0000000057b0c000 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:190 [inline]
do_idle+0x1e7/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x3ae/0x410 init/main.c:1111
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147