rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5257/1:b..l
(detected by 1, t=10503 jiffies, g=17769, q=221 ncpus=2)
task:syz.0.187 state:R running task stack:26496 pid:5257 ppid:4265 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:ffffc9000d8b7660 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: d8bb7651cc127900
RDX: 0000000000000000 RSI: ffffffff8a6c1780 RDI: ffffffff8abef920
RBP: ffffc9000d8b7770 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: 0000000000000000
R13: 1ffff92001b16ed8 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
percpu_ref_put+0x35/0x180 include/linux/percpu-refcount.h:351
css_put include/linux/cgroup.h:407 [inline]
__mem_cgroup_charge+0x52/0x80 mm/memcontrol.c:6945
mem_cgroup_charge include/linux/memcontrol.h:672 [inline]
shmem_add_to_page_cache+0x8fc/0x1c00 mm/shmem.c:708
shmem_get_folio_gfp+0x158b/0x3400 mm/shmem.c:1971
shmem_get_folio mm/shmem.c:2072 [inline]
shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
generic_perform_write+0x2f7/0x5a0 mm/filemap.c:3862
__generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960
generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x44c/0x960 fs/read_write.c:584
ksys_write+0x143/0x240 fs/read_write.c:637
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: 0033:0x7ff5cdf8e1ff
RSP: 002b:00007ff5ced76df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000013bd7ef RCX: 00007ff5cdf8e1ff
RDX: 00000000013bd7ef RSI: 00007ff5c3df7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000557b
R10: 000020000000bbc2 R11: 0000000000000293 R12: 0000000000000003
R13: 00007ff5ced76ef0 R14: 00007ff5ced76eb0 R15: 00007ff5c3df7000
rcu: rcu_preempt kthread starved for 10537 jiffies! g17769 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:27400 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:2168
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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5220 Comm: syz.3.180 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__lock_acquire+0x1b7/0x7c50 kernel/locking/lockdep.c:4952
Code: 04 00 84 c0 0f 85 bc 64 00 00 41 8b 06 48 89 44 24 60 48 c7 c0 40 f1 9c 96 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 c4 64 00 00 <83> 3d 22 e8 39 15 00 75 0b 83 7c 24 60 30 0f 83 a6 57 00 00 44 89
RSP: 0018:ffffc900000077c0 EFLAGS: 00000097
RAX: 0000000000000004 RBX: ffff88804a68ae58 RCX: ffffffff969cf103
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88804a68ae58
RBP: ffffc90000007a10 R08: dffffc0000000000 R09: 0000000000000001
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: ffff8880303d8000
R13: 0000000000000001 R14: ffff8880303d8ad8 R15: ffffffff90257a80
FS: 00007f40fd08f6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff04dce998 CR3: 0000000064999000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
__lock_task_sighand+0x146/0x2d0 kernel/signal.c:1411
lock_task_sighand include/linux/sched/signal.h:745 [inline]
send_sigqueue+0x159/0x600 kernel/signal.c:1979
posix_timer_event kernel/time/posix-timers.c:360 [inline]
posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386
__run_hrtimer kernel/time/hrtimer.c:1747 [inline]
__hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811
hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
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 ae 05 49 f7 48 89 df e8 06 cb 49 f7 e8 d1 bd 6c f7 fb bf 01 00 00 00 96 43 3d f7 65 8b 05 27 f1 e7 75 85 c0 74 02 5b c3 e8 c4 02 e6
RSP: 0018:ffffc900032c7b98 EFLAGS: 00000282
RAX: f4646e75af7e0000 RBX: ffff88804a68ae40 RCX: f4646e75af7e0000
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: 0000000000000001
RBP: ffff88804a68b0d8 R08: dffffc0000000000 R09: ffffed10094d15c9
R10: ffffed10094d15c9 R11: 1ffff110094d15c8 R12: 1ffff110094d161b
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb7/0x1240 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: 0033:0x7f40fc18f749
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:00007f40fd08f0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f40fc3e5fa8 RCX: 00007f40fc18f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f40fc3e5fa8
RBP: 00007f40fc3e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f40fc3e6038 R14: 00007ffdb6e25020 R15: 00007ffdb6e25108