rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11451/1:b..l P11399/1:b..l
(detected by 0, t=10503 jiffies, g=57045, q=12 ncpus=2)
task:syz.2.1754 state:R running task stack:25984 pid:11399 ppid:4267 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:792 [inline]
RIP: 0010:page_ext_get+0x3e/0x2a0 mm/page_ext.c:157
Code: bd 90 ff 48 8d 1d 00 00 00 00 48 c7 c7 e0 ab b2 8c 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 e8 e6 d7 87 ff 48 83 c4 08 0d 7f 3c 08 89 c5 31 ff 89 c6 e8 c2 b8 a5 ff 85 ed 74 10 e8 a9
RSP: 0018:ffffc9000c8a7088 EFLAGS: 00000286
RAX: c9f3deb7c5c51f00 RBX: ffffffff81db195e RCX: c9f3deb7c5c51f00
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefd20
RBP: dffffc0000000000 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 00fff00000000000
R13: 0000000000000000 R14: ffffea00013c2580 R15: ffffea00013c2580
__page_table_check_zero+0x134/0x4b0 mm/page_table_check.c:146
page_table_check_free include/linux/page_table_check.h:46 [inline]
free_pages_prepare mm/page_alloc.c:1460 [inline]
free_pcp_prepare mm/page_alloc.c:1509 [inline]
free_unref_page_prepare+0x8c4/0x9a0 mm/page_alloc.c:3384
free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
release_pages+0x1f92/0x2200 mm/swap.c:1035
__pagevec_release+0x6d/0xe0 mm/swap.c:1055
pagevec_release include/linux/pagevec.h:71 [inline]
folio_batch_release include/linux/pagevec.h:135 [inline]
shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
shmem_truncate_range mm/shmem.c:1062 [inline]
shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
evict+0x485/0x870 fs/inode.c:705
__dentry_kill+0x431/0x650 fs/dcache.c:611
dentry_kill+0xb8/0x290 fs/dcache.c:-1
dput+0xfa/0x1d0 fs/dcache.c:918
__fput+0x5e0/0x920 fs/file_table.c:328
task_work_run+0x1ca/0x250 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0x93e/0x2400 kernel/exit.c:880
do_group_exit+0x217/0x2d0 kernel/exit.c:1022
get_signal+0x1272/0x1350 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
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:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1892f8eec9
RSP: 002b:00007f1893dce038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 000000000000fffd RBX: 00007f18931e6090 RCX: 00007f1892f8eec9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f1893011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f18931e6128 R14: 00007f18931e6090 R15: 00007ffe64fc40f8
task:syz.0.1770 state:R running task stack:25248 pid:11451 ppid:4269 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000c64f3e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: aefaf082e4d8a800
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefd20
RBP: ffffc9000c64f4f8 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: 0000000000000001
R13: 1ffff920018c9e88 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
blk_cgroup_congested+0x37/0x220 block/blk-cgroup.c:2012
__cgroup_throttle_swaprate+0x6d/0x1a0 mm/swapfile.c:3671
cgroup_throttle_swaprate include/linux/swap.h:672 [inline]
folio_throttle_swaprate include/linux/swap.h:681 [inline]
shmem_add_to_page_cache+0x9c1/0x1c00 mm/shmem.c:717
shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
shmem_fault+0x1be/0x7b0 mm/shmem.c:2156
__do_fault+0x13b/0x4e0 mm/memory.c:4280
do_read_fault mm/memory.c:4631 [inline]
do_fault mm/memory.c:4760 [inline]
handle_pte_fault mm/memory.c:5031 [inline]
__handle_mm_fault mm/memory.c:5173 [inline]
handle_mm_fault+0x28ca/0x3e70 mm/memory.c:5294
faultin_page mm/gup.c:1026 [inline]
__get_user_pages+0x3ff/0xeb0 mm/gup.c:1250
populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607
__mm_populate+0x248/0x370 mm/gup.c:1721
mm_populate include/linux/mm.h:2891 [inline]
vm_mmap_pgoff+0x203/0x2b0 mm/util.c:525
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f72d9d8eec9
RSP: 002b:00007f72dabf8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f72d9fe5fa0 RCX: 00007f72d9d8eec9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f72d9e11f91 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f72d9fe6038 R14: 00007f72d9fe5fa0 R15: 00007ffe667cf1d8
rcu: rcu_preempt kthread starved for 10593 jiffies! g57045 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:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 11452 Comm: syz.4.1771 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f5 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 6e c8 41 f7 48 89 df e8 c6 8d 42 f7 e8 f1 7f 65 f7 fb bf 01 00 00 00 16 0b 36 f7 65 8b 05 17 c4 e0 75 85 c0 74 02 5b c3 e8 64 d5 de
RSP: 0018:ffffc9000d5efbb8 EFLAGS: 00000286
RAX: 7a50bbb96a75dc00 RBX: ffff88807aef0000 RCX: 7a50bbb96a75dc00
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: 0000000000000001
RBP: 1ffff1100fc0f0ed R08: dffffc0000000000 R09: ffffed100f5de001
R10: ffffed100f5de001 R11: 1ffff1100f5de000 R12: ffff88807d1b0920
R13: 0000000000000000 R14: dffffc0000000000 R15: ffff88807d1b0938
FS: 00007fb1a317e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000055833000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
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:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb1a238eec9
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:00007fb1a317e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb1a25e5fa8 RCX: 00007fb1a238eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb1a25e5fa8
RBP: 00007fb1a25e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb1a25e6038 R14: 00007fff405d2970 R15: 00007fff405d2a58