rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7853/1:b..l P7848/1:b..l P6384/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=27381, q=590 ncpus=2)
task:syz-executor state:R running task stack:19496 pid:6384 tgid:6384 ppid:6381 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:101 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x4e8/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: ff df 4c 8b 64 24 20 4c 8b 6c 24 48 0f 84 79 15 00 00 e9 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 <48> c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef
RSP: 0018:ffffc900041bea58 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff8fb9e1b0 RCX: 0000000000000000
RDX: ffffffff8fb9e190 RSI: ffffffff90355c12 RDI: ffffffff8be07900
RBP: ffffffff8fb9e1b0 R08: 0000000000000009 R09: ffffffff8e13f2e0
R10: ffffc900041beb88 R11: fffff52000837d7d R12: ffffffff81745867
R13: ffffffff8fb9e1ac R14: ffffc900041beb88 R15: ffffffff8fb9e1ac
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__set_page_owner+0x8d/0x4c0 mm/page_owner.c:341
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline]
alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2577
pagetable_alloc_noprof include/linux/mm.h:3237 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:76 [inline]
pte_alloc_one+0x23/0x370 arch/x86/mm/pgtable.c:18
__pte_alloc+0x25/0x1a0 mm/memory.c:453
copy_pte_range mm/memory.c:1237 [inline]
copy_pmd_range+0x7931/0x8060 mm/memory.c:1392
copy_pud_range mm/memory.c:1429 [inline]
copy_p4d_range mm/memory.c:1453 [inline]
copy_page_range+0xb88/0x11d0 mm/memory.c:1535
dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827
dup_mm kernel/fork.c:1533 [inline]
copy_mm+0x14f/0x770 kernel/fork.c:1585
copy_process+0x165d/0x3950 kernel/fork.c:2225
kernel_clone+0x21e/0x820 kernel/fork.c:2655
__do_sys_clone kernel/fork.c:2796 [inline]
__se_sys_clone kernel/fork.c:2780 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2780
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4733385e93
RSP: 002b:00007fff18e7a528 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4733385e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556e7947d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000003ac1b R15: 00007fff18e7a6c0
task:syz.5.329 state:R running task stack:25336 pid:7848 tgid:7846 ppid:6241 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893
Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 2a 0f 01 11 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9
RSP: 0018:ffffc900140d7278 EFLAGS: 00000206
RAX: 228136fb402f1e00 RBX: 0000000000000202 RCX: 228136fb402f1e00
RDX: 0000000000000002 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: ffff88807d00e700 R08: ffff88801c6791b7 R09: 1ffff110038cf236
R10: dffffc0000000000 R11: ffffed10038cf237 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8e13f2e0 R15: ffff88807d00db80
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
__update_page_owner_handle+0x51a/0x570 mm/page_owner.c:270
__set_page_owner+0x10b/0x4c0 mm/page_owner.c:342
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2505
shmem_alloc_folio mm/shmem.c:1902 [inline]
shmem_alloc_and_add_folio+0x423/0xf40 mm/shmem.c:1944
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2568
shmem_get_folio mm/shmem.c:2674 [inline]
shmem_write_begin+0x16c/0x330 mm/shmem.c:3327
generic_perform_write+0x2c5/0x900 mm/filemap.c:4314
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3502
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5c9/0xb30 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8d2cf8e1ff
RSP: 002b:00007f8d2dd96df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f8d2cf8e1ff
RDX: 0000000001000000 RSI: 00007f8d22c00000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005f10
R10: 000000000000076a R11: 0000000000000293 R12: 0000000000000003
R13: 00007f8d2dd96ef0 R14: 00007f8d2dd96eb0 R15: 00007f8d22c00000
task:syz.8.274 state:R running task stack:27320 pid:7853 tgid:7853 ppid:7836 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320
Code: 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 cc cc cc cc cc 0f 1f 80 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 04 24 65 48 8b 0c 25 08 b0 9f 92 65 8b 15 d8 f2
RSP: 0018:ffffc9001410f540 EFLAGS: 00000246
RAX: fff0000000000fdb RBX: 00007fd5d12ed000 RCX: 0000000000000000
RDX: ffff8880313e8000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff821461e9 R09: ffffffff8e13f2e0
R10: ffffc9001410f820 R11: fffff52002821f06 R12: fff0000000000fdb
R13: 000000007723f067 R14: ffff88806a45b448 R15: 0000000000000000
pmd_pfn_mask arch/x86/include/asm/pgtable_types.h:453 [inline]
pmd_flags_mask arch/x86/include/asm/pgtable_types.h:461 [inline]
pmd_flags arch/x86/include/asm/pgtable_types.h:466 [inline]
pmd_bad arch/x86/include/asm/pgtable.h:1035 [inline]
___pte_offset_map+0x193/0x240 mm/pgtable-generic.c:299
__pte_offset_map include/linux/mm.h:3393 [inline]
__pte_offset_map_lock+0x46/0x210 mm/pgtable-generic.c:399
pte_offset_map_lock include/linux/mm.h:3408 [inline]
zap_pte_range mm/memory.c:1840 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3d29/0x44e0 mm/memory.c:2017
unmap_single_vma mm/memory.c:2059 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2101
exit_mmap+0x239/0xb10 mm/mmap.c:1277
__mmput+0x118/0x430 kernel/fork.c:1177
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x850/0x25b0 kernel/exit.c:959
__do_sys_exit kernel/exit.c:1079 [inline]
__se_sys_exit kernel/exit.c:1077 [inline]
__x64_sys_exit+0x40/0x40 kernel/exit.c:1077
x64_sys_call+0x21f3/0x2210 arch/x86/include/generated/asm/syscalls_64.h:61
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5d178f749
RSP: 002b:00007fd5d25e2fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007fd5d19e6180 RCX: 00007fd5d178f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd5d1813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd5d19e6218 R14: 00007fd5d19e6180 R15: 00007ffcd6151ab8
rcu: rcu_preempt kthread starved for 10627 jiffies! g27381 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:27168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5258 [inline]
__schedule+0x150e/0x5070 kernel/sched/core.c:6866
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:schedule+0x0/0x360 kernel/sched/core.c:6954
Code: 89 34 24 48 8b 84 24 a0 00 00 00 4c 89 20 e9 cc e9 ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 49 bd 00 00 00 00 00 fc
RSP: 0018:ffffc90000157a18 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 00000000ffffe890 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8d997e54 RDI: 00000000ffffffff
RBP: ffffc90000157b10 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 1ffff9200002af44
R13: 1ffffffff1bc2250 R14: ffffc90000157a40 R15: dffffc0000000000
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 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:
CPU: 0 UID: 0 PID: 7857 Comm: syz.1.331 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a 4e 3e f6 48 89 df e8 52 c5 3e f6 e8 4d 43 69 f6 fb bf 01 00 00 00 82 ba 30 f6 65 8b 05 db 5f 3f 07 85 c0 74 07 5b e9 c1 4b 00 00
RSP: 0018:ffffc9000b9ffc60 EFLAGS: 00000286
RAX: 55c5df75ea5f6800 RBX: ffff88802a5965c0 RCX: 55c5df75ea5f6800
RDX: 0000000000000000 RSI: ffffffff8d997e54 RDI: 0000000000000001
RBP: 0000000000000021 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee
R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 1ffff110054b2d4b
R13: 0000000000000000 R14: 000000001c000004 R15: ffff88802a596a58
FS: 00007fa29234a6c0(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa28f7f6d58 CR3: 00000000618aa000 CR4: 00000000003526f0
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11a7/0x1340 kernel/signal.c:3037
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa29158f747
Code: ff ff 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
RSP: 002b:00007fa29234a038 EFLAGS: 00000246
RAX: 0000000000000013 RBX: 00007fa2917e5fa0 RCX: 00007fa29158f749
RDX: 0000000000000001 RSI: 0000200000000340 RDI: 0000000000000004
RBP: 00007fa291613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa2917e6038 R14: 00007fa2917e5fa0 R15: 00007ffdd3101e58