rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7841/1:b..l P9111/1:b..l P9422/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=36653, q=384 ncpus=2)
task:syz.2.770 state:R running task stack:23864 pid:9422 tgid:9422 ppid:5831 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [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+0x38bc/0x4170 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:1173
exit_mm+0x169/0x230 kernel/exit.c:581
do_exit+0x627/0x22f0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 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+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdc8b18f749
RSP: 002b:00007ffd6e52c018 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdc8b18f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd6e52c07c R08: 0000000a6e52c10f R09: 00000000000927c0
R10: 00000000000000cc R11: 0000000000000246 R12: 00000000000000c0
R13: 00000000000927c0 R14: 0000000000077396 R15: 00007ffd6e52c0d0
task:udevd state:R running task stack:23608 pid:9111 tgid:9111 ppid:5194 task_flags:0x20440140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:864 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1890
__blk_mq_issue_directly block/blk-mq.c:2715 [inline]
blk_mq_request_issue_directly+0x3c1/0x710 block/blk-mq.c:2802
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2823
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2898
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2981
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225
blk_finish_plug+0x5e/0x90 block/blk-core.c:1252
read_pages+0x3b2/0x580 mm/readahead.c:176
page_cache_ra_unbounded+0x750/0x990 mm/readahead.c:302
do_page_cache_ra mm/readahead.c:332 [inline]
force_page_cache_ra mm/readahead.c:361 [inline]
page_cache_sync_ra+0x433/0xc40 mm/readahead.c:579
filemap_get_pages+0x468/0x1dc0 mm/filemap.c:2690
filemap_read+0x3f6/0x11a0 mm/filemap.c:2800
blkdev_read_iter+0x30a/0x440 block/fops.c:856
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x55a/0xa30 fs/read_write.c:572
ksys_read+0x145/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45e90a7407
RSP: 002b:00007ffdd1245db0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f45e97de880 RCX: 00007f45e90a7407
RDX: 0000000000000200 RSI: 00007f45e97bf000 RDI: 0000000000000009
RBP: 0000556ef8281050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000020000 R14: 0000556ef8288e18 R15: 00007f45e990539c
task:udevd state:R running task stack:24280 pid:7841 tgid:7841 ppid:5194 task_flags:0x400140 flags:0x00080800
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 20 b1 bb 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0a 20 e2 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 da 50 72 ff cc 48 8d 3d 37 7a e7
RSP: 0018:ffffc9000433f0d8 EFLAGS: 00000286
RAX: bf50ae72d1072600 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000005a44979c RSI: ffffffff8d97608a RDI: ffffffff8bc083e0
RBP: ffffffff8173fd65 R08: ffffffff8173fd65 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffffff81acf3d0 R12: 0000000000000002
R13: ffffffff8df41aa0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:3000
folios_put_refs+0x584/0x670 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x49e/0x1490 mm/shmem.c:1137
shmem_truncate_range mm/shmem.c:1249 [inline]
shmem_evict_inode+0x26e/0xa70 mm/shmem.c:1379
evict+0x5f4/0xae0 fs/inode.c:837
__dentry_kill+0x209/0x660 fs/dcache.c:670
finish_dput+0xc9/0x480 fs/dcache.c:879
__fput+0x68e/0xa70 fs/file_table.c:476
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xef/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f45e90a7407
RSP: 002b:00007ffdd124b260 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f45e97de880 RCX: 00007f45e90a7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f45e97de6e8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
R13: 0000556ef8281190 R14: 0000000000000008 R15: 0000556ef8295f30
rcu: rcu_preempt kthread starved for 10628 jiffies! g36653 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:27632 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x510/0xa50 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 1e a4 b6 f5 cc cc cc 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 53 b1 0e 00 f3 0f 1e fa fb f4 f3 a3 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07dc0 EFLAGS: 000002c6
RAX: 0000000001330177 RBX: ffffffff819713ee RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d792134 RDI: ffffffff8bc083e0
RBP: ffffffff8dc07eb0 R08: ffff8880b86336db R09: 1ffff110170c66db
R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8f822570
R13: 1ffffffff1b92a68 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f45e97c0000 CR3: 000000007659f000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1be/0x4d0 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:757
start_kernel+0x381/0x3d0 init/main.c:1206
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147