rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12325/1:b..l P12361/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=41657, q=328 ncpus=2)
task:syz.3.1465 state:R running task stack:26648 pid:12361 tgid:12360 ppid:5815 task_flags:0x400140 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:__orc_find+0x20/0xf0 arch/x86/kernel/unwind_orc.c:91
Code: 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 55 49 89 cd 89 d1 41 54 4c 8d 64 8f fc 55 53 48 83 ec 08 85 d2 0f 84 99 00 00 00 <49> 89 fe 48 89 f0 49 39 fc 72 7b 48 b9 00 00 00 00 00 fc ff df 49
RSP: 0018:ffffc90003916cb8 EFLAGS: 00000202
RAX: ffffffff912f82be RBX: 0000000000000001 RCX: 0000000000000008
RDX: 0000000000000008 RSI: ffffffff912f82be RDI: ffffffff90a742c0
RBP: ffffc90003916db0 R08: ffffffff912f82ee R09: 000000002accd784
R10: 0000000000000002 R11: 00000000000125bf R12: ffffffff90a742dc
R13: ffffffff8225bf95 R14: ffffc90003916d9d R15: ffffffff8225bf95
orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
unwind_next_frame+0x2ec/0x20b0 arch/x86/kernel/unwind_orc.c:510
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:1846
prep_new_page mm/page_alloc.c:1854 [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_fault+0x1fe/0xa00 mm/shmem.c:2757
__do_fault+0x10d/0x490 mm/memory.c:5320
do_read_fault mm/memory.c:5755 [inline]
do_fault+0xae4/0x1ad0 mm/memory.c:5889
do_pte_missing mm/memory.c:4401 [inline]
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault+0x1919/0x2bb0 mm/memory.c:6411
handle_mm_fault+0x3fe/0xad0 mm/memory.c:6580
faultin_page mm/gup.c:1126 [inline]
__get_user_pages+0x54e/0x3590 mm/gup.c:1428
populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
__mm_populate+0x1d8/0x380 mm/gup.c:1963
mm_populate include/linux/mm.h:3701 [inline]
vm_mmap_pgoff+0x37f/0x470 mm/util.c:586
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
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: 0033:0x7f9548d8f749
RSP: 002b:00007f9549cfb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f9548fe5fa0 RCX: 00007f9548d8f749
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f9548e13f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9548fe6038 R14: 00007f9548fe5fa0 R15: 00007ffe644cc2d8
task:syz.5.1454 state:R running task stack:24760 pid:12325 tgid:12325 ppid:8201 task_flags:0x40004c flags:0x00080001
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:__sanitizer_cov_trace_const_cmp8+0x0/0x20 kernel/kcov.c:320
Code: 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 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 48 89 f2 48 89 fe bf 07 00 00 00 e9 f8 fd
RSP: 0018:ffffc90003a9f378 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000000007df57 RCX: ffffffff8234ebca
RDX: ffff88804cbba4c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88801ca80000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88804cbbaff0 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 00000000023c0289
page_ext_invalid mm/page_ext.c:245 [inline]
lookup_page_ext+0x9f/0x100 mm/page_ext.c:261
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__update_page_owner_free_handle.constprop.0+0xaa/0x4a0 mm/page_owner.c:284
__reset_page_owner+0x93/0x1a0 mm/page_owner.c:321
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000
folios_put_refs+0x4be/0x750 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x58f/0x1140 mm/shmem.c:1137
shmem_truncate_range mm/shmem.c:1249 [inline]
shmem_evict_inode+0x39e/0xbe0 mm/shmem.c:1379
evict+0x3c2/0xad0 fs/inode.c:837
iput_final fs/inode.c:1951 [inline]
iput.part.0+0x621/0x1190 fs/inode.c:2003
iput+0x35/0x40 fs/inode.c:1966
dentry_unlink_inode+0x29c/0x480 fs/dcache.c:467
__dentry_kill+0x1d0/0x600 fs/dcache.c:670
finish_dput+0x76/0x480 fs/dcache.c:879
dput.part.0+0x451/0x570 fs/dcache.c:928
dput+0x1f/0x30 fs/dcache.c:920
__fput+0x51c/0xb70 fs/file_table.c:476
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x87f/0x2bd0 kernel/exit.c:971
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121
x64_sys_call+0x151c/0x1740 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f6b66f8f749
RSP: 002b:00007fff70075e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6b66f8f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff70075ecc R08: 0000000d70075f5f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000097
R13: 00000000000927c0 R14: 000000000007cbed R15: 00007fff70075f20
rcu: rcu_preempt kthread starved for 10508 jiffies! g41657 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:28168 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: 12335 Comm: syz.0.1457 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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: e9 4d 1b 5e 00 be 03 00 00 00 5b e9 12 dd ed 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 78 c9 f3 11 65 8b 05 89 c9 f3 11 a9 00 01 ff 00 74 1d
RSP: 0018:ffffc90003947c90 EFLAGS: 00000246
RAX: 1ffff110059d49ed RBX: 00007f4b53172428 RCX: 0000000000000000
RDX: 00000000000000c0 RSI: ffffffff84accd98 RDI: ffffc90003947ce8
RBP: 00000000000000c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88802cea54b0 R12: 0000000000000007
R13: ffffc90003947ce8 R14: 0000000000000000 R15: ffff88802cea4980
FS: 00007f4b531736c0(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b53173040 CR3: 0000000076113000 CR4: 00000000003526f0
Call Trace:
_inline_copy_from_user include/linux/uaccess.h:169 [inline]
_copy_from_user+0x18/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:223 [inline]
restore_sigcontext+0xcb/0x6a0 arch/x86/kernel/signal_64.c:59
__do_sys_rt_sigreturn+0x229/0x2c0 arch/x86/kernel/signal_64.c:268
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: 0033:0x7f4b5232b829
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007f4b53172400 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f4b525e6098 RCX: 00007f4b5232b829
RDX: 00007f4b53172400 RSI: 00007f4b53172530 RDI: 0000000000000021
RBP: 00007f4b525e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f4b525e6128 R14: 00007ffcac23ac90 R15: 00007ffcac23ad78