rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5774/1:b..l P6342/1:b..l P5770/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=14553, q=391 ncpus=2)
task:syz-executor state:R running task stack:21672 pid:5770 ppid:5767 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x36/0x80 kernel/kcov.c:320
Code: 20 3f 7c 7e 65 8b 15 21 3f 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00 00 74 4e 8b 91 f8 15 00 00 <83> fa 03 75 43 48 8b 91 00 16 00 00 44 8b 89 fc 15 00 00 49 c1 e1
RSP: 0018:ffffc90004577680 EFLAGS: 00000246
RAX: ffffffff81eae0e9 RBX: ffffffff81eae022 RCX: ffff888023b23c00
RDX: 0000000000000000 RSI: 0000000000056901 RDI: 00000003ffffffff
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000056901 R15: ffffea00015a4040
__nr_to_section include/linux/mmzone.h:1845 [inline]
__pfn_to_section include/linux/mmzone.h:1957 [inline]
lookup_page_ext mm/page_ext.c:237 [inline]
page_ext_get+0xe9/0x2b0 mm/page_ext.c:509
__reset_page_owner+0x2e/0x190 mm/page_owner.c:145
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1182 [inline]
free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366
free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2505
release_pages+0x208a/0x2300 mm/swap.c:1022
__folio_batch_release+0x71/0xe0 mm/swap.c:1042
folio_batch_release include/linux/pagevec.h:83 [inline]
shmem_undo_range+0x5ff/0x1a80 mm/shmem.c:1026
shmem_truncate_range mm/shmem.c:1135 [inline]
shmem_evict_inode+0x285/0xa70 mm/shmem.c:1264
evict+0x4b7/0x8a0 fs/inode.c:705
do_unlinkat+0x38c/0x590 fs/namei.c:4410
__do_sys_unlink fs/namei.c:4451 [inline]
__se_sys_unlink fs/namei.c:4449 [inline]
__x64_sys_unlink+0x49/0x50 fs/namei.c:4449
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3bac59cf87
RSP: 002b:00007fffbaa47668 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3bac59cf87
RDX: 00007fffbaa47690 RSI: 00007fffbaa47720 RDI: 00007fffbaa47720
RBP: 00007fffbaa47720 R08: 00007fffbaa48720 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffbaa487b0
R13: 00007f3bac63330a R14: 000000000002833c R15: 00007fffbaa487f0
task:syz.0.117 state:R running task stack:24952 pid:6342 ppid:5778 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6868
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6892
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2577/0x32f0 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3302
__mmput+0x118/0x3a0 kernel/fork.c:1362
exit_mm+0x23f/0x340 kernel/exit.c:570
do_exit+0x909/0x2530 kernel/exit.c:871
do_group_exit+0x22d/0x2f0 kernel/exit.c:1026
get_signal+0x12a6/0x1390 kernel/signal.c:2903
arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7d5a39de99
RSP: 002b:00007f7d5b1b10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7d5a626098 RCX: 00007f7d5a39de99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7d5a626098
RBP: 00007f7d5a626090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7d5a626128 R14: 00007ffc36201e70 R15: 00007ffc36201f58
task:syz-executor state:R running task stack:21800 pid:5774 ppid:5768 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:699
Code: 8a e8 3e 9b 1b 09 48 c7 c7 00 86 13 8d 4c 89 f6 e8 2f 0b f4 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 d8 7e 92 7e e8 fb b0 1b 09 89 c3 83 f8 08 73 60
RSP: 0000:ffffc90004527678 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888027ed5a00
RDX: 0000000000000000 RSI: 0000000000055b96 RDI: 00000003ffffffff
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff223d6a0
R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: dffffc0000000000
R13: 0000000000000140 R14: 0000000000055b96 R15: ffff888019180000
rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
rcu_read_lock_held+0x15/0x40 kernel/rcu/update.c:348
lookup_page_ext mm/page_ext.c:240 [inline]
page_ext_get+0x193/0x2b0 mm/page_ext.c:509
__page_table_check_zero+0x138/0x4b0 mm/page_table_check.c:148
page_table_check_free include/linux/page_table_check.h:41 [inline]
free_pages_prepare mm/page_alloc.c:1183 [inline]
free_unref_page_prepare+0x7e6/0x8f0 mm/page_alloc.c:2366
free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2505
release_pages+0x208a/0x2300 mm/swap.c:1022
__folio_batch_release+0x71/0xe0 mm/swap.c:1042
folio_batch_release include/linux/pagevec.h:83 [inline]
shmem_undo_range+0x5ff/0x1a80 mm/shmem.c:1026
shmem_truncate_range mm/shmem.c:1135 [inline]
shmem_evict_inode+0x285/0xa70 mm/shmem.c:1264
evict+0x4b7/0x8a0 fs/inode.c:705
do_unlinkat+0x38c/0x590 fs/namei.c:4410
__do_sys_unlink fs/namei.c:4451 [inline]
__se_sys_unlink fs/namei.c:4449 [inline]
__x64_sys_unlink+0x49/0x50 fs/namei.c:4449
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a3639cf87
RSP: 002b:00007fffc0bf5c08 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6a3639cf87
RDX: 00007fffc0bf5c30 RSI: 00007fffc0bf5cc0 RDI: 00007fffc0bf5cc0
RBP: 00007fffc0bf5cc0 R08: 00007fffc0bf6cc0 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffc0bf6d50
R13: 00007f6a3643330a R14: 00000000000294a0 R15: 00007fffc0bf6d90
rcu: rcu_preempt kthread starved for 10618 jiffies! g14553 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:27160 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 5e 1c 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d a3 6a 3b 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c2
RAX: 86824c3269ffb100 RBX: ffffffff81630c31 RCX: 86824c3269ffb100
RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1d0660
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36bab R09: 1ffff110171c6d75
R10: dffffc0000000000 R11: ffffed10171c6d76 R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c4379c7 CR3: 000000007483a000 CR4: 00000000003506f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x221/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:744
arch_call_rest_init+0xe/0x10 init/main.c:840
start_kernel+0x461/0x4e0 init/main.c:1085
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b