rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10500 ticks this GP) idle=640c/1/0x4000000000000000 softirq=7809/7810 fqs=1
(t=10502 jiffies g=5649 q=145 ncpus=2)
rcu: rcu_preempt kthread starved for 10501 jiffies! g5649 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:27848 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4293 Comm: syz-executor250 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lock_release+0x13c/0x910 kernel/locking/lockdep.c:-1
Code: 8b 35 d8 fa 9e 7e 49 8d 9e dc 0a 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 43 05 00 00 83 3b 00 0f 85 4e 04 00 00 <4c> 89 74 24 08 48 c7 84 24 a0 00 00 00 00 00 00 00 9c 8f 84 24 a0
RSP: 0018:ffffc90003cf7bc0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88802538641c RCX: bb9ac575c9334300
RDX: 0000000000000000 RSI: ffffffff8adefac0 RDI: ffffffff8adefa80
RBP: ffffc90003cf7ce0 R08: dffffc0000000000 R09: fffffbfff1c3ee26
R10: fffffbfff1c3ee26 R11: 1ffffffff1c3ee25 R12: ffff888025385940
R13: dffffc0000000000 R14: ffff888025385940 R15: 1ffff9200079ef84
FS: 00005555876be3c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f899665b6e0 CR3: 0000000029533000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:157 [inline]
_raw_spin_unlock_irq+0x12/0x40 kernel/locking/spinlock.c:202
__ia32_sys_rt_sigreturn+0x184/0x790 arch/x86/kernel/signal.c:673
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: 0033:0x7f899665b6e9
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007ffd64c58e00 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f899665b6e9
RDX: 00007ffd64c58e00 RSI: 00007ffd64c58f30 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f899669917c
R13: 00007f8996692152 R14: 00007ffd64c593f0 R15: 0000000000000000
CPU: 1 PID: 4292 Comm: syz-executor250 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:ffffc90003ce7b40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 92d7ec5d53819b00
RDX: 0000000000000000 RSI: ffffffff8a8c1480 RDI: ffffffff8adefae0
RBP: ffffc90003ce7c50 R08: dffffc0000000000 R09: fffffbfff215c24f
R10: fffffbfff215c24f R11: 1ffffffff215c24e R12: 0000000000000001
R13: 1ffff9200079cf74 R14: 0000000000000246 R15: dffffc0000000000
FS: 00005555876be3c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f899665b6e0 CR3: 000000002893c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__might_fault+0xc2/0x120 mm/memory.c:5852
__clear_user arch/x86/include/asm/uaccess_64.h:96 [inline]
clear_user arch/x86/include/asm/uaccess_64.h:124 [inline]
copy_siginfo_to_user+0xca/0x140 kernel/signal.c:3341
__setup_rt_frame arch/x86/kernel/signal.c:491 [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+0xd2e/0x1230 arch/x86/kernel/signal.c:873
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: 0033:0x7f8996642149
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 1d 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd64c593b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f8996642149
RDX: 0000200000000240 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f899669917c
R13: 00007f8996692152 R14: 00007ffd64c593f0 R15: 0000000000000000