rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8271/1:b..l P8301/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=33981, q=167 ncpus=2)
task:syz.1.583 state:R running task stack:22856 pid:8301 tgid:8301 ppid:5597 task_flags:0x40064c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x125e/0x6990 kernel/sched/core.c:7382
preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7662
irqentry_exit_cond_resched arch/x86/include/asm/fred.h:105 [inline]
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:453 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline]
irqentry_exit+0x33f/0xab0 kernel/entry/common.c:154
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5947
Code: 05 8f a5 a6 13 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 9e 7c 5d 10 0f 82 c9 02 00 00 8b 35 3e ae 5d 10 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 2d a5 a6 13 0f 85 09 03 00 00 48 83 c4
RSP: 0018:ffffc9001bcdeea8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e3bfab7 RDI: ffffffff8c625e80
RBP: ffffffff8fdecde0 R08: 00000000ef9d33e4 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [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:183
__reset_page_owner+0x84/0x190 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
free_unref_folios+0xa4a/0x1790 mm/page_alloc.c:3022
folios_put_refs+0x585/0xaa0 mm/folio.c:1036
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x5db/0x1560 mm/shmem.c:1161
shmem_truncate_range mm/shmem.c:1289 [inline]
shmem_evict_inode+0x3b1/0xca0 mm/shmem.c:1420
evict+0x3c2/0xad0 fs/inode.c:822
iput_final fs/inode.c:2014 [inline]
iput.part.0+0x989/0x1050 fs/inode.c:2063
iput+0x30/0x40 fs/inode.c:2029
dentry_unlink_inode+0x403/0x4d0 fs/dcache.c:493
dentry_kill+0x25d/0xca0 fs/dcache.c:840
finish_dput fs/dcache.c:1015 [inline]
dput.part.0+0xd2/0x240 fs/dcache.c:1056
dput+0x1f/0x30 fs/dcache.c:1051
__fput+0x515/0xb50 fs/file_table.c:520
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x8da/0x2a40 kernel/exit.c:987
do_group_exit+0xd5/0x2a0 kernel/exit.c:1130
get_signal+0x1ec2/0x21d0 kernel/signal.c:3112
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [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+0x542/0xab0 kernel/entry/common.c:152
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x0
RSP: 002b:00002000000002c8 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc554626180 RCX: 00007fc55439f559
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000020000
RBP: 00007fc554436b20 R08: 00002000000007c0 R09: 00002000000007c0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc554626218 R14: 00007fc554626180 R15: 00007ffe29241148
task:syz.4.574 state:R running task stack:23208 pid:8271 tgid:8271 ppid:5599 task_flags:0xc00640 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x125e/0x6990 kernel/sched/core.c:7382
preempt_schedule_notrace+0x57/0xd0 kernel/sched/core.c:7633
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x90/0xc0 kernel/rcu/tree.c:754
rcu_read_lock_held_common kernel/rcu/update.c:109 [inline]
rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
lookup_page_ext+0x6e/0x100 mm/page_ext.c:253
page_ext_iter_begin include/linux/page_ext.h:136 [inline]
__page_table_check_zero+0x11c/0x410 mm/page_table_check.c:139
page_table_check_alloc include/linux/page_table_check.h:38 [inline]
post_alloc_hook+0xed/0x120 mm/page_alloc.c:1872
prep_new_page mm/page_alloc.c:1879 [inline]
get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
__alloc_frozen_pages_noprof+0x2e9/0x32e0 mm/page_alloc.c:5436
alloc_pages_mpol+0x201/0x550 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2505
shmem_alloc_folio+0x135/0x160 mm/shmem.c:1936
shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1978
shmem_get_folio_gfp+0x756/0x1980 mm/shmem.c:2531
shmem_get_folio mm/shmem.c:2637 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3268
generic_perform_write+0x292/0xa40 mm/filemap.c:4374
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3443
__kernel_write_iter+0x2ac/0x930 fs/read_write.c:621
dump_write_iter fs/coredump.c:1358 [inline]
dump_emit_page fs/coredump.c:1531 [inline]
dump_user_range+0xa0d/0xe90 fs/coredump.c:1599
elf_core_dump+0x2d97/0x3d60 fs/binfmt_elf.c:2106
coredump_write fs/coredump.c:1150 [inline]
do_coredump fs/coredump.c:1235 [inline]
vfs_coredump+0x26af/0x58f0 fs/coredump.c:1310
get_signal+0x1f25/0x21d0 kernel/signal.c:3097
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop kernel/entry/common.c:101 [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+0x542/0xab0 kernel/entry/common.c:152
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f830c79f561
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f830ca26090 RCX: 00007f830c79f559
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f830c836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f830ca26128 R14: 00007f830ca26090 R15: 00007ffd411b4928
rcu: rcu_preempt kthread starved for 10428 jiffies! g33981 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27400 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x125e/0x6990 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7474
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x930 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x179/0x260 kernel/rcu/tree.c:2330
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 77 95 02 e9 93 55 03 00 0f 1f 00 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 13 eb 15 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197e00 EFLAGS: 00000246
RAX: 00000000010791f5 RBX: ffff88801fee2580 RCX: ffffffff8bd5d315
RDX: 0000000000000001 RSI: ffffffff8e3e5c32 RDI: ffffffff8c625e80
RBP: ffffed1003fdc4b0 R08: 0000000000000001 R09: ffffed1017066815
R10: ffff8880b83340ab R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888122a34000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6d3ce844fd CR3: 000000007331a000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:768
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x158