rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 0, t=10502 jiffies, g=9373, q=77 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294960888-4294950385), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g9373 f0x2 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:27496 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5836 Comm: syz-executor165 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4798 [inline]
RIP: 0010:__lock_acquire+0x954/0x7c80 kernel/locking/lockdep.c:5087
Code: 89 c6 41 81 e6 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 20 55 da 90 be 08 00 00 00 e8 b4 3f 77 00 4c 0f a3 35 cc 4d 73 0f <73> 1a 49 69 c6 d0 00 00 00 4c 8d b0 e0 d3 70 90 49 b8 00 00 00 00
RSP: 0018:ffffc900001f0880 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8167074c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da55f0
RBP: ffffc900001f0ac8 R08: ffffffff90da55f7 R09: 1ffffffff21b4abe
R10: dffffc0000000000 R11: fffffbfff21b4abf R12: 0000000000000000
R13: ffff88807d698b00 R14: 00000000000006a9 R15: ffff88807d698b00
FS: 0000555564e77480(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd52b5fc80 CR3: 000000007af2b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
__lock_task_sighand+0x46/0x2d0 kernel/signal.c:1407
lock_task_sighand include/linux/sched/signal.h:742 [inline]
send_sigqueue+0x239/0x710 kernel/signal.c:2009
posix_timer_event kernel/time/posix-timers.c:299 [inline]
posix_timer_fn+0x16e/0x3d0 kernel/time/posix-timers.c:325
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
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: 00 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 9a 78 ef f6 48 89 df e8 b2 4a f0 f6 e8 8d f7 13 f7 fb bf 01 00 00 00 <e8> f2 61 e3 f6 65 8b 05 03 b8 8b 75 85 c0 74 02 5b c3 e8 e0 99 88
RSP: 0018:ffffc90004617c98 EFLAGS: 00000282
RAX: 950f770bc61d2000 RBX: ffff88802bf74a00 RCX: 950f770bc61d2000
RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: 0000000000000001
RBP: ffff88802bf74e98 R08: ffffffff8e4a7e2f R09: 1ffffffff1c94fc5
R10: dffffc0000000000 R11: fffffbfff1c94fc6 R12: 1ffff110057ee9d3
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x11f5/0x1400 kernel/signal.c:2905
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f57ce62c8da
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 68 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 68 02 00 8b 44 24
RSP: 002b:00007ffd52b61d30 EFLAGS: 00000293
RAX: fffffffffffffff7 RBX: 0000000000000008 RCX: 00007f57ce62c8da
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f57ce68851c
R13: 00007f57ce682125 R14: 00007ffd52b61d80 R15: 0000000000000000
</TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.302 msecs