rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10499 ticks this GP) idle=800c/1/0x4000000000000000 softirq=9825/9825 fqs=28
(t=10500 jiffies g=9893 q=741 ncpus=2)
rcu: rcu_preempt kthread starved for 10434 jiffies! g9893 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:27840 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
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: 4499 Comm: syz.3.19 Not tainted 6.1.144-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_acquire+0x15e/0x490 kernel/locking/lockdep.c:5658
Code: 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 19 02 00 00 41 83 3e 00 0f 85 02 01 00 00 48 c7 84 24 a0 00 00 00 00 00 00 00 9c <8f> 84 24 a0 00 00 00 4c 8b b4 24 a0 00 00 00 fa 48 c7 c7 40 11 8c
RSP: 0018:ffffc900037e7998 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 7ac32d21cb572400
RDX: 0000000000000000 RSI: ffffffff8adf1c00 RDI: ffffffff8adf1bc0
RBP: ffffc900037e7aa8 R08: dffffc0000000000 R09: fffffbfff1c3ecc6
R10: fffffbfff1c3ecc6 R11: 1ffffffff1c3ecc5 R12: 0000000000000000
R13: 1ffff920006fcf40 R14: ffff88807c9de41c R15: dffffc0000000000
FS: 00005555581f0500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dc5ffff CR3: 0000000077859000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
__lock_timer+0x55/0x3f0 kernel/time/posix-timers.c:631
posixtimer_rearm+0x5c/0x340 kernel/time/posix-timers.c:324
dequeue_signal+0x1b6/0x4b0 kernel/signal.c:704
get_signal+0x547/0x1350 kernel/signal.c:2751
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
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: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: 0033:0x7fb852984097
Code: 24 08 64 48 2b 14 25 28 00 00 00 75 05 48 83 c4 18 c3 e8 0c db 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 8b 05 71 a6 1f 00 <48> 85 c0 74 14 48 83 ec 08 ff d0 85 c0 75 1a 31 c0 48 83 c4 08 c3
RSP: 002b:00007ffe403094c8 EFLAGS: 00000206
RAX: 00007ffe403a9910 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 00007fb852a99960 RSI: 00007ffe40309520 RDI: 0000000000000001
RBP: 00007fb852a299a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb852bb5fa0 R14: 00007fb852bb5fa0 R15: 0000000000000004
CPU: 1 PID: 4495 Comm: syz.0.24 Not tainted 6.1.144-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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 ce 81 41 f7 48 89 df e8 26 47 42 f7 e8 41 49 65 f7 fb bf 01 00 00 00 36 c4 35 f7 65 8b 05 07 85 e0 75 85 c0 74 02 5b c3 e8 54 96 de
RSP: 0018:ffffc900035d7bb8 EFLAGS: 00000286
RAX: 78a9e87de44dc900 RBX: ffff88807a69c0c0 RCX: 78a9e87de44dc900
RDX: dffffc0000000000 RSI: ffffffff8a8c0460 RDI: 0000000000000001
RBP: ffff88807a69c358 R08: dffffc0000000000 R09: ffffed100f4d3819
R10: ffffed100f4d3819 R11: 1ffff1100f4d3818 R12: 1ffff1100f4d386b
R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000000000000
FS: 000055555ab6e500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d65ffff CR3: 000000007edf0000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
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: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: 0033:0x7f4b9d860c65
Code: 80 00 00 00 00 48 83 c4 28 48 c7 c0 ff ff ff ff 5b 5d c3 66 90 41 57 41 56 41 55 41 54 55 53 48 83 ec 38 80 3d 9b 13 35 00 00 <89> 7c 24 0c 88 54 24 10 48 89 74 24 28 0f 85 c8 09 00 00 80 3d 65
RSP: 002b:00007ffc6b596010 EFLAGS: 00000246
RAX: 00007f4b9dbb5fa0 RBX: 00007f4b9dbb5fa8 RCX: 0000000000000000
RDX: 00000000fffffc03 RSI: 00007f4b9dbb6038 RDI: 0000000000000003
RBP: 00007f4b9dbb5fb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00007f4b9dbb5fa0
R13: 0000200000000000 R14: 00007ffc6b596088 R15: 0000000000000004