rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=1c0c/1/0x4000000000000000 softirq=58278/58287 fqs=2
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5823/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=46337, q=396 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11312 Comm: syz-executor Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:preempt_count_sub+0xe/0x160 kernel/sched/core.c:5884
Code: 48 c7 c7 60 91 aa 93 e9 20 43 68 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 c7 c0 e0 65 b3 9a 53 89 fb <48> ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0
RSP: 0018:ffffc90000a08d70 EFLAGS: 00000046
RAX: ffffffff9ab365e0 RBX: 0000000000000001 RCX: ffffffff81985ed3
RDX: dffffc0000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffff88803328f400 R08: 0000000000000000 R09: ffffed10066c565d
R10: ffff88803362b2eb R11: 0000000000000000 R12: 184b5c2f00000000
R13: 184b5c2f00000000 R14: 0000000000000000 R15: ffff88803328e800
FS: 000055556b7dc500(0000) GS:ffff888124adf000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f108a8e56c0 CR3: 0000000057455000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x28/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
advance_sched+0x62b/0xc80 net/sched/sch_taprio.c:981
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 4a 9f 28 f6 48 89 df e8 f2 f2 28 f6 e8 2d 8b 53 f6 fb bf 01 00 00 00 52 5f 19 f6 65 8b 05 8b a4 34 08 85 c0 74 06 5b c3 cc cc cc cc
RSP: 0018:ffffc9000dca7500 EFLAGS: 00000202
RAX: 00000000001023cd RBX: ffff88802b1cd008 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff8dbe121f RDI: 0000000000000001
RBP: 00000000000004f3 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90850517 R11: 0000000000000000 R12: ffff888148f83700
R13: 00000000000004f3 R14: dffffc0000000000 R15: 0000000000000033
spin_unlock_irq include/linux/spinlock.h:401 [inline]
clear_shadow_from_swap_cache+0x33c/0x4c0 mm/swap_state.c:208
swap_range_free mm/swapfile.c:1148 [inline]
swap_entry_range_free+0x3eb/0x800 mm/swapfile.c:1537
__swap_entry_free mm/swapfile.c:1465 [inline]
__swap_entries_free mm/swapfile.c:1503 [inline]
free_swap_and_cache_nr+0x5e4/0x830 mm/swapfile.c:1800
shmem_free_swap+0xac/0xd0 mm/shmem.c:961
shmem_undo_range+0x3c0/0x1150 mm/shmem.c:1115
shmem_truncate_range mm/shmem.c:1237 [inline]
shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1365
evict+0x3e3/0x920 fs/inode.c:810
iput_final fs/inode.c:1898 [inline]
iput fs/inode.c:1924 [inline]
iput+0x521/0x880 fs/inode.c:1910
do_unlinkat+0x518/0x6a0 fs/namei.c:4650
__do_sys_unlink fs/namei.c:4689 [inline]
__se_sys_unlink fs/namei.c:4687 [inline]
__x64_sys_unlink+0xc5/0x110 fs/namei.c:4687
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa80eb8df17
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 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:00007ffc4041e208 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa80eb8df17
RDX: 00007ffc4041e230 RSI: 00007ffc4041e2c0 RDI: 00007ffc4041e2c0
RBP: 00007ffc4041e2c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc4041f350
R13: 00007fa80ec1089d R14: 00000000000400e5 R15: 00007ffc4041f390
task:syz-executor state:R running task stack:23560 pid:5823 tgid:5823 ppid:5803 task_flags:0x400140 flags:0x00000000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090
irqentry_exit+0x36/0x90 kernel/entry/common.c:354
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870
Code: fe 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 42 f3 ec 0e 0f 82 74 02 00 00 8b 35 da 22 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 19 fe 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9000458eec0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3bf5c0 RCX: 000000009d994fd0
RDX: 0000000000000000 RSI: ffffffff8dbbbc2f RDI: ffffffff8bf48260
RBP: 0000000000000002 R08: e2ccb7f23d347ab8 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__set_page_owner+0x91/0x550 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1718
prep_new_page mm/page_alloc.c:1726 [inline]
get_page_from_freelist+0x135c/0x3920 mm/page_alloc.c:3688
__alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4970
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2392
pagetable_alloc_noprof include/linux/mm.h:3002 [inline]
__pud_alloc_one_noprof include/asm-generic/pgalloc.h:172 [inline]
pud_alloc_one_noprof include/asm-generic/pgalloc.h:193 [inline]
__pud_alloc+0x39/0x690 mm/memory.c:6623
pud_alloc include/linux/mm.h:2959 [inline]
copy_pud_range mm/memory.c:1272 [inline]
copy_p4d_range mm/memory.c:1316 [inline]
copy_page_range+0x3a6d/0x5fe0 mm/memory.c:1410
dup_mmap kernel/fork.c:726 [inline]
dup_mm kernel/fork.c:1734 [inline]
copy_mm kernel/fork.c:1786 [inline]
copy_process+0x862b/0x91a0 kernel/fork.c:2429
kernel_clone+0xfc/0x960 kernel/fork.c:2844
__do_sys_clone+0xce/0x120 kernel/fork.c:2987
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1089b851d3
RSP: 002b:00007ffd4d15a848 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1089b851d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555590c1e7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000400d2 R15: 00007ffd4d15a9e0
rcu: rcu_preempt kthread starved for 10495 jiffies! g46337 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:27704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 6772 Comm: kworker/u8:21 Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:246
Code: 8b 05 a8 e3 e8 11 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 3c 16 00 00 85 c0 74 4f <8b> 82 18 16 00 00 83 f8 03 75 44 48 8b 82 20 16 00 00 8b 92 1c 16
RSP: 0018:ffffc9000ca27930 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff8880b853f740 RCX: ffffffff81af1bb9
RDX: ffff88802e08c880 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170a7ee9
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b843b040
FS: 0000000000000000(0000) GS:ffff8881249df000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f165b37d2d8 CR3: 000000000e180000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
csd_lock_wait kernel/smp.c:340 [inline]
smp_call_function_many_cond+0x4c9/0x1290 kernel/smp.c:885
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2455 [inline]
text_poke_bp_batch+0x220/0x760 arch/x86/kernel/alternative.c:2665
text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
text_poke_flush arch/x86/kernel/alternative.c:2853 [inline]
text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x376/0x550 kernel/jump_label.c:919
static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:850 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245