rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=7d3c/1/0x4000000000000000 softirq=74826/74826 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5623/1:b..l P15104/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=84709, q=195 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 15164 Comm: syz.0.2428 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4786 [inline]
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4776 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4875 [inline]
RIP: 0010:__lock_acquire+0x2b9/0x2630 kernel/locking/lockdep.c:5187
Code: 00 0f b6 7e 21 44 31 cf 83 e7 60 74 e4 44 8d 48 01 65 8b 05 c1 6b 25 12 85 c0 0f 84 d5 04 00 00 8b 85 60 0b 00 00 85 c0 75 10 <44> 8b bd 78 0b 00 00 45 85 ff 0f 84 e6 0b 00 00 41 bf 03 00 00 00
RSP: 0018:ffffc90000007c80 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888032455610 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88803749a2c0
RBP: ffff888032454a80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000c42 R14: 0000000000000000 R15: 0000000000000003
FS: 00007f533d18d6c0(0000) GS:ffff888124387000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f533c44f156 CR3: 0000000059e61000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b1/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
spin_lock include/linux/spinlock.h:342 [inline]
advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:write_comp_data+0x2b/0x90 kernel/kcov.c:272
Code: 8b 05 b9 e5 00 12 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 90 e5 00 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 00 12 84 09 8b 87 ec 16 00 00 85 c0 74 f1 8b 87 c8 16 00 00 83
RSP: 0018:ffffc9000359fc88 EFLAGS: 00000297
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff81c6b8d5
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888032454a80
RBP: ffff8880b85284c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: fffffbfff21ae34a
R13: 1ffff920006b3f9f R14: 0000000000000000 R15: 0000000000000000
rcu_sync_is_idle include/linux/rcu_sync.h:34 [inline]
percpu_up_read include/linux/percpu-rwsem.h:118 [inline]
cpus_read_unlock+0x35/0x150 kernel/cpu.c:502
class_cpus_read_lock_destructor include/linux/cpuhplock.h:48 [inline]
clock_was_set+0x657/0x870 kernel/time/hrtimer.c:988
do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603
do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
__do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline]
__x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f533c39ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f533d18d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007f533c615fa0 RCX: 00007f533c39ce59
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000
RBP: 00007f533c432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f533c616038 R14: 00007f533c615fa0 R15: 00007ffef2ca1bb8
task:syz.5.2411 state:R running task stack:23688 pid:15104 tgid:15104 ppid:11836 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x970 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5844 [inline]
RIP: 0010:lock_acquire+0x155/0x370 kernel/locking/lockdep.c:5825
Code: 0d b4 c0 f2 0e 85 c9 0f 84 bd 00 00 00 65 8b 05 49 4a 25 12 85 c0 0f 85 ae 00 00 00 65 48 8b 05 c9 02 25 12 8b 90 8c 0b 00 00 <85> d2 0f 85 98 00 00 00 9c 8f 04 24 fa 48 c7 c7 56 0d 00 8e e8 52
RSP: 0018:ffffc9000780e308 EFLAGS: 00000246
RAX: ffff88807a24a540 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81b7cec1 RDI: fffffbfff1cfcaac
RBP: ffffffff8e7e5560 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 000000000001444f R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__set_page_owner+0x8c/0x540 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x11a6/0x3410 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5221
alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490
folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1933
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1975
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2564
shmem_get_folio mm/shmem.c:2670 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3303
generic_perform_write+0x292/0xa40 mm/filemap.c:4325
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3478
__kernel_write_iter+0x2ac/0x920 fs/read_write.c:621
dump_emit_page fs/coredump.c:1304 [inline]
dump_user_range+0x3f9/0xad0 fs/coredump.c:1378
elf_core_dump+0x2d5f/0x3d10 fs/binfmt_elf.c:2109
coredump_write fs/coredump.c:1053 [inline]
do_coredump fs/coredump.c:1132 [inline]
vfs_coredump+0x2980/0x5770 fs/coredump.c:1206
get_signal+0x2162/0x2210 kernel/signal.c:3023
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x39e/0x970 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fd0fb39ce61
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd0fb616090 RCX: 00007fd0fb39ce59
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fd0fb432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fd0fb616128 R14: 00007fd0fb616090 R15: 00007ffc51318388
task:syz-executor state:R running task stack:22328 pid:5623 tgid:5623 ppid:5611 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7370
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+0x3e/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
copy_pte_range mm/memory.c:1347 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x1c1f/0x5b20 mm/memory.c:1555
dup_mmap+0xd44/0x21b0 mm/mmap.c:1840
dup_mm kernel/fork.c:1534 [inline]
copy_mm kernel/fork.c:1586 [inline]
copy_process+0x6c78/0x7ed0 kernel/fork.c:2264
kernel_clone+0x176/0x9e0 kernel/fork.c:2722
__do_sys_clone+0xd9/0x120 kernel/fork.c:2863
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f77c3fc58d2
RSP: 002b:00007ffe9a0b20a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe9a0b20a0 RCX: 00007f77c3fc58d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe9a0b222c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555833ba7d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00005555833cda10 R14: 00000000000c2c26 R15: 00007ffe9a0b2280
rcu: rcu_preempt kthread starved for 10500 jiffies! g84709 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:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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:
CPU: 1 UID: 0 PID: 5956 Comm: kworker/u8:13 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 96 7e 5c 00 48 89 df 5b e9 5d 0f 62 00 be 03 00 00 00 5b e9 52 b0 f0 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 a5 de 00 12 48 8b 34 24 65 48 8b 15 81 de 00
RSP: 0018:ffffc90004bef868 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fc2dfd
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802e7e2540
RBP: ffff8880b8443560 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886ad R14: 0000000000000001 R15: ffff8880b853c800
FS: 0000000000000000(0000) GS:ffff888124487000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000aed000 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x587/0x1700 kernel/smp.c:892
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:906 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245