rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5522/3:b..l P4981/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=166593, q=764 ncpus=2)
task:syz.4.6824 state:R running task stack:22760 pid:4981 tgid:4981 ppid:23221 task_flags:0x40064c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__rcu_read_unlock+0xf3/0x550 kernel/rcu/tree_plugin.h:441
Code: 00 00 85 c0 75 57 65 48 8b 1d e1 dc 34 12 48 8d bb 44 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 7d 01 00 00 8b
RSP: 0018:ffffc9000b1c72d0 EFLAGS: 00000a07
RAX: dffffc0000000000 RBX: ffff888033a20000 RCX: ffffc9000b1c72c4
RDX: 0000000000000000 RSI: ffffffff8de2a0c5 RDI: ffff888033a20444
RBP: ffff888033a20000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888033a20000
R13: 0000000000000001 R14: fffffffffffffffe R15: 000000000000001a
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
page_ref_add_unless.constprop.0+0x122/0x390 include/linux/page_ref.h:239
folio_ref_add_unless include/linux/page_ref.h:248 [inline]
folio_try_get include/linux/page_ref.h:264 [inline]
find_get_entry mm/filemap.c:2051 [inline]
find_lock_entries+0x1c1/0xbf0 mm/filemap.c:2141
shmem_undo_range+0x216/0x1150 mm/shmem.c:1139
shmem_truncate_range mm/shmem.c:1269 [inline]
shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1397
evict+0x3e3/0x920 fs/inode.c:810
iput_final fs/inode.c:1897 [inline]
iput fs/inode.c:1923 [inline]
iput+0x521/0x880 fs/inode.c:1909
dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466
__dentry_kill+0x1d0/0x600 fs/dcache.c:669
dput.part.0+0x4b1/0x9b0 fs/dcache.c:911
dput+0x1f/0x30 fs/dcache.c:901
__fput+0x51c/0xb70 fs/file_table.c:476
task_work_run+0x14d/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:961
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x13e/0x290 kernel/entry/common.c:73
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x0
RSP: 002b:000000000000000a EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fd9d1bd6180 RCX: 00007fd9d198ec29
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007fd9d1a11e41 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd9d1bd6218 R14: 00007fd9d1bd6180 R15: 00007ffe94f02218
task:syz.3.6861 state:R running task stack:23424 pid:5522 tgid:5522 ppid:25314 task_flags:0x400640 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
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+0x3e/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
filemap_map_pages+0xe15/0x1670 mm/filemap.c:3791
do_fault_around mm/memory.c:5531 [inline]
do_read_fault mm/memory.c:5564 [inline]
do_fault mm/memory.c:5707 [inline]
do_pte_missing+0xe36/0x3ba0 mm/memory.c:4234
handle_pte_fault mm/memory.c:6052 [inline]
__handle_mm_fault+0x152a/0x2a50 mm/memory.c:6195
handle_mm_fault+0x589/0xd10 mm/memory.c:6364
faultin_page mm/gup.c:1144 [inline]
__get_user_pages+0x551/0x34a0 mm/gup.c:1446
__get_user_pages_locked mm/gup.c:1712 [inline]
get_dump_page+0x257/0x3d0 mm/gup.c:2212
dump_user_range+0x195/0xb70 fs/coredump.c:1364
elf_core_dump+0x2929/0x3b60 fs/binfmt_elf.c:2085
coredump_write fs/coredump.c:1049 [inline]
vfs_coredump+0x2b97/0x5670 fs/coredump.c:1168
get_signal+0x22e3/0x26d0 kernel/signal.c:3019
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x13e/0x290 kernel/entry/common.c:73
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x9e
RSP: 002b:0000200000000018 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc92f7d5fa0 RCX: 00007fc92f58ec29
RDX: 0000200000000040 RSI: 0000200000000010 RDI: 000000008416c480
RBP: 00007fc92f611e41 R08: 00002000000000c0 R09: 00002000000000c0
R10: 0000200000000080 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fc92f7d6038 R14: 00007fc92f7d5fa0 R15: 00007ffcc191ecc8
rcu: rcu_preempt kthread starved for 10519 jiffies! g166593 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:27928 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
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 U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 2d 64 02 e9 13 0a 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 53 65 18 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:ffffc90000197df8 EFLAGS: 000002c6
RAX: 0000000000d51c59 RBX: 0000000000000001 RCX: ffffffff8b91ab29
RDX: 0000000000000000 RSI: ffffffff8de4f5da RDI: ffffffff8c163780
RBP: ffffed1003c55b40 R08: 0000000000000001 R09: ffffed10170a6655
R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001
R13: ffff88801e2ada00 R14: ffffffff90abab90 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881247ba000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f833b55c63a CR3: 0000000022732000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x391/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x148