rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21247/1:b..l P21234/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=103593, q=131 ncpus=2)
task:syz.5.3696 state:R running task stack:24136 pid:21234 tgid:21234 ppid:18414 task_flags:0x400640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 22 bd ee 0e 0f 82 74 02 00 00 8b 35 ba ed ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 39 b4 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc90004be6330 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 00000000e8ca1250
RDX: 0000000000000000 RSI: ffffffff8daa80f3 RDI: ffffffff8bf2b380
RBP: 0000000000000002 R08: 00000000fac62354 R09: 000000004fac6235
R10: 0000000000000002 R11: ffff88802863d4b0 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495
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:165
__set_page_owner+0x91/0x560 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x36/0x2f0 mm/mempolicy.c:2505
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1890
shmem_alloc_and_add_folio+0x494/0xc20 mm/shmem.c:1932
shmem_get_folio_gfp+0x67f/0x1610 mm/shmem.c:2556
shmem_get_folio mm/shmem.c:2662 [inline]
shmem_write_begin+0x1a4/0x3b0 mm/shmem.c:3315
generic_perform_write+0x3c4/0x900 mm/filemap.c:4314
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3490
__kernel_write_iter+0x31a/0xb10 fs/read_write.c:619
dump_emit_page fs/coredump.c:1298 [inline]
dump_user_range+0x413/0xb70 fs/coredump.c:1372
elf_core_dump+0x29c3/0x3c10 fs/binfmt_elf.c:2111
coredump_write fs/coredump.c:1049 [inline]
do_coredump fs/coredump.c:1126 [inline]
vfs_coredump+0x2b85/0x55e0 fs/coredump.c:1200
get_signal+0x22e1/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f02f038f751
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f02f05e6090 RCX: 00007f02f038f749
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f02f0413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f02f05e6128 R14: 00007f02f05e6090 R15: 00007ffdc10fdd48
task:syz.2.3698 state:R running task stack:28040 pid:21247 tgid:21242 ppid:18672 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kasan_check_byte+0x1c/0x50 mm/kasan/common.c:578
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 54 49 89 f4 55 48 89 fd 53 e8 8d 25 00 00 89 c3 84 c0 74 0b 89 d8 5b <5d> 41 5c e9 cc b0 52 09 4c 89 e1 48 89 ef 31 d2 be 01 00 00 00 e8
RSP: 0018:ffffc9000420f220 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8e3c96a0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff816cb681 RDI: fffffbfff1c792d4
RBP: ffffffff8e3c96a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000012887 R12: ffffffff816cb681
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire kernel/locking/lockdep.c:5842 [inline]
lock_acquire+0xfc/0x330 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6878
tomoyo_realpath_from_path+0x19f/0x6e0 security/tomoyo/realpath.c:286
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771
tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
security_file_open+0x84/0x1e0 security/security.c:2636
do_dentry_open+0x597/0x1590 fs/open.c:939
vfs_open+0x82/0x3f0 fs/open.c:1094
do_open fs/namei.c:4628 [inline]
path_openat+0x2078/0x3140 fs/namei.c:4787
do_filp_open+0x20b/0x470 fs/namei.c:4814
do_sys_openat2+0x121/0x290 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92f298df90
RSP: 002b:00007f92f380cf10 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f92f298df90
RDX: 0000000000000002 RSI: 00007f92f380cfa0 RDI: 00000000ffffff9c
RBP: 00007f92f380cfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f92f2be6128 R14: 00007f92f2be6090 R15: 00007ffd08e28a88
rcu: rcu_preempt kthread starved for 10608 jiffies! g103593 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:27688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21232 Comm: syz.5.3696 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:313
Code: 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff
RSP: 0018:ffffc900152ef6b8 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000010 RCX: ffffc90012e6b000
RDX: 0000000000080000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88804f7cd280 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88802f120b30 R12: 0000000000000000
R13: 0000000000010000 R14: ffff8880237a0b90 R15: 0000000000000000
FS: 00007f02ee5f66c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009cdd6000 CR4: 00000000003526f0
Call Trace:
kvm_register_mark_available arch/x86/kvm/kvm_cache_regs.h:83 [inline]
vmx_cache_reg+0x76/0x5e0 arch/x86/kvm/vmx/vmx.c:2596
kvm_register_read_raw+0x1e1/0x240 arch/x86/kvm/kvm_cache_regs.h:119
kvm_rip_read arch/x86/kvm/kvm_cache_regs.h:136 [inline]
init_emulate_ctxt+0x1a9/0x510 arch/x86/kvm/x86.c:8965
x86_decode_emulated_instruction arch/x86/kvm/x86.c:9368 [inline]
x86_emulate_instruction+0x826/0x1c00 arch/x86/kvm/x86.c:9422
kvm_mmu_page_fault+0xbfd/0x1c60 arch/x86/kvm/mmu/mmu.c:6464
__vmx_handle_ept_violation arch/x86/kvm/vmx/common.h:108 [inline]
handle_ept_violation+0x2df/0x710 arch/x86/kvm/vmx/vmx.c:5905
__vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6760 [inline]
vmx_handle_exit+0x129b/0x1a00 arch/x86/kvm/vmx/vmx.c:6770
vcpu_enter_guest arch/x86/kvm/x86.c:11481 [inline]
vcpu_run+0x3468/0x5a80 arch/x86/kvm/x86.c:11639
kvm_arch_vcpu_ioctl_run+0xfd3/0x1860 arch/x86/kvm/x86.c:11984
kvm_vcpu_ioctl+0x76d/0x16d0 virt/kvm/kvm_main.c:4492
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f02f038f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f02ee5f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f02f05e5fa0 RCX: 00007f02f038f749
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000007
RBP: 00007f02f0413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f02f05e6038 R14: 00007f02f05e5fa0 R15: 00007ffdc10fdd48