rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 0, t=10502 jiffies, g=15801, q=96 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4294965825-4294955324), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g15801 f0x2 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+0x10ec/0x40b0 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:
CPU: 0 PID: 5490 Comm: syz.0.288 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_release+0x593/0x910 kernel/locking/lockdep.c:5686
Code: 00 00 00 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 75 75 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 66 43 c7 44 2f 09 00 00 43 c6 44 2f 0b 00
RSP: 0018:ffffc9000cc079a0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: 186c26465aaa4100
RDX: 0000000000000000 RSI: ffffffff8a8c1680 RDI: ffffffff8adefd20
RBP: ffffc9000cc07ab0 R08: dffffc0000000000 R09: fffffbfff1c3ecb6
R10: fffffbfff1c3ecb6 R11: 1ffffffff1c3ecb5 R12: ffff88802a080ae0
R13: dffffc0000000000 R14: ffff88802a080ad0 R15: 1ffff92001980f40
FS: 00007fd8f3b906c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd8f2fe5fac CR3: 000000007d85f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__copy_to_user include/linux/uaccess.h:111 [inline]
save_xstate_epilog arch/x86/kernel/fpu/signal.c:127 [inline]
copy_fpstate_to_sigframe+0xa53/0xcb0 arch/x86/kernel/fpu/signal.c:245
get_sigframe arch/x86/kernel/signal.c:297 [inline]
__setup_rt_frame arch/x86/kernel/signal.c:472 [inline]
setup_rt_frame arch/x86/kernel/signal.c:784 [inline]
handle_signal arch/x86/kernel/signal.c:828 [inline]
arch_do_signal_or_restart+0x610/0x1230 arch/x86/kernel/signal.c:873
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: 0033:0x7fd8f2d8eec9
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:00007fd8f3b900e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fd8f2fe5fa8 RCX: 00007fd8f2d8eec9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fd8f2fe5fac
RBP: 00007fd8f2fe5fa0 R08: 00137339de2038ac R09: 0000000000000000
R10: 00000000000000b4 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd8f2fe6038 R14: 00007ffeb499a8c0 R15: 00007ffeb499a9a8