rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=c6f4/1/0x4000000000000000 softirq=11804/11806 fqs=6
(t=10501 jiffies g=11797 q=577 ncpus=2)
rcu: rcu_preempt kthread starved for 10490 jiffies! g11797 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:27200 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4534 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:mark_lock+0x101/0x320 kernel/locking/lockdep.c:4647
Code: 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 b4 55 6d 00 b8 01 00 00 00 45 85 27 74 50 48 83 c4 08 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 e8 66 47 a0 02 85 c0 74 c1 48 c7 c0 e8 42 ff 8d 48 c1
RSP: 0018:ffffc900001e0a48 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffff88801a358ac4 RCX: ffffffff8163bb14
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff908c8248
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff211904a
R10: fffffbfff211904a R11: 1ffffffff2119049 R12: ffff88801a358000
R13: ffff88801a358b02 R14: ffff88801a358ae0 R15: ffffffff902547d0
FS: 00005555944ba500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000180 CR3: 00000000787ae000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
mark_usage kernel/locking/lockdep.c:4549 [inline]
__lock_acquire+0xd6f/0x7c50 kernel/locking/lockdep.c:5003
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
hrtimer_interrupt+0xf8/0x9c0 kernel/time/hrtimer.c:1854
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:ffffc90003337b98 EFLAGS: 00000282
RAX: ad53aaa3e1a73f00 RBX: ffff88802813ca00 RCX: ad53aaa3e1a73f00
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: 0000000000000001
RBP: ffff88802813cc98 R08: dffffc0000000000 R09: ffffed1005027941
R10: ffffed1005027941 R11: 1ffff11005027940 R12: 1ffff11005027993
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: 0033:0x7f7707b8f749
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:00007ffd9d6ce858 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f7707de5fa8 RCX: 00007f7707b8f749
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7707de5fac
RBP: 0000000000000000 R08: 0026f170d4457906 R09: 000000089d6ceb4f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7707de5fac
R13: 00007f7707de5fa0 R14: 0000000000001da6 R15: 0000000000000004
CPU: 0 PID: 4532 Comm: syz.3.25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0xcd/0x910 kernel/locking/lockdep.c:5673
Code: d9 8b 9b 0c 0f 83 22 05 00 00 41 89 de c1 eb 06 48 8d 3c dd 28 0e ff 8d be 08 00 00 00 e8 3b 8e 6d 00 4c 0f a3 35 ab 89 9b 0c <73> 0d e8 ec 99 07 00 84 c0 0f 84 29 05 00 00 48 c7 c0 e4 42 ff 8d
RSP: 0018:ffffc90003757aa0 EFLAGS: 00000257
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81638475
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8dff0e28
RBP: ffffc90003757bc0 R08: dffffc0000000000 R09: fffffbfff1bfe1c6
R10: fffffbfff1bfe1c6 R11: 1ffffffff1bfe1c5 R12: 1ffff920006eaf88
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920006eaf60
FS: 00005555927eb500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc00eb1fc0 CR3: 000000001db80000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
_copy_from_user+0x27/0x170 lib/usercopy.c:14
copy_from_user include/linux/uaccess.h:161 [inline]
restore_altstack+0x9a/0x4a0 kernel/signal.c:4257
__ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:678
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: 0033:0x7fae6f784da6
Code: c4 18 c3 e8 2c dc 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 05 71 e9 22 00 48 85 c0 74 14 48 83 ec 08 ff d0 85 c0 75 1a <31> c0 48 83 c4 08 c3 0f 1f 00 b8 e4 00 00 00 0f 05 85 c0 75 1d 31
RSP: 002b:00007ffc00eb2570 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fae6f825af7 RCX: 00000000000000fc
RDX: 000000838d80f46d RSI: 00007ffc00eb25a0 RDI: 000000003a69dd2d
RBP: 0000000000000000 R08: 00000000000000fc R09: 003a04449ccc97a6
R10: 000000838ca171a1 R11: 000000000000aed2 R12: 00007fae6f9e5fac
R13: 00007fae6f9e5fa0 R14: 00000000000012db R15: 0000000000000004
sched: RT throttling activated