rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10498 ticks this GP) idle=73f4/0/0x1 softirq=20659/20659 fqs=0 (t=10500 jiffies g=23749 q=44 ncpus=2) rcu: rcu_preempt kthread starved for 10500 jiffies! g23749 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:28144 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6918 Comm: syz.1.603 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_region_inline mm/kasan/generic.c:172 [inline] RIP: 0010:kasan_check_range+0x1f/0x290 mm/kasan/generic.c:189 Code: 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 a4 01 00 00 41 57 41 56 53 49 89 f8 49 01 f0 0f 82 57 02 00 00 49 89 f8 <49> c1 e8 2f 41 81 f8 ff ff 01 00 0f 82 43 02 00 00 49 bf 01 00 00 RSP: 0018:ffffc900001e06e0 EFLAGS: 00000082 RAX: 0000000000000001 RBX: ffff88802c608000 RCX: ffffffff81639a34 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ade250 RBP: 0000000000000000 R08: ffffffff90ade250 R09: fffffbfff215bc49 R10: fffffbfff215bc49 R11: 1ffffffff215bc48 R12: 0000000000000001 R13: dffffc0000000000 R14: ffff88802c608b30 R15: 00000000000000a2 FS: 00007f854c9f66c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000032000 CR3: 00000000795ee000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] mark_lock+0x94/0x320 kernel/locking/lockdep.c:4606 mark_usage kernel/locking/lockdep.c:4520 [inline] __lock_acquire+0xc25/0x7c50 kernel/locking/lockdep.c:5003 reacquire_held_locks+0x2f9/0x590 kernel/locking/lockdep.c:5187 __lock_release kernel/locking/lockdep.c:5376 [inline] lock_release+0x340/0x910 kernel/locking/lockdep.c:5682 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock include/linux/rcupdate.h:824 [inline] __lock_task_sighand+0x2b0/0x2d0 kernel/signal.c:1416 lock_task_sighand include/linux/sched/signal.h:745 [inline] send_sigqueue+0x159/0x600 kernel/signal.c:1979 posix_timer_event kernel/time/posix-timers.c:360 [inline] posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386 __run_hrtimer kernel/time/hrtimer.c:1752 [inline] __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1816 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1878 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 fe f8 42 f7 48 89 df e8 56 be 43 f7 e8 61 b0 66 f7 fb bf 01 00 00 00 06 3c 37 f7 65 8b 05 57 05 e2 75 85 c0 74 02 5b c3 e8 a4 16 e0 RSP: 0018:ffffc90004f87bb8 EFLAGS: 00000286 RAX: 3077773907b84700 RBX: ffff888058a8e5c0 RCX: 3077773907b84700 RDX: dffffc0000000000 RSI: ffffffff8a8c0420 RDI: 0000000000000001 RBP: ffff888058a8ea58 R08: dffffc0000000000 R09: ffffed100b151cb9 R10: ffffed100b151cb9 R11: 1ffff1100b151cb8 R12: 1ffff1100b151d4b R13: 0000000000000021 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+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: 0033:0x7f854e78ebe7 Code: ff ff 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 RSP: 002b:00007f854c9f60e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f854e9b5fa8 RCX: 00007f854e78ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f854e9b5fa8 RBP: 00007f854e9b5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f854e9b6038 R14: 00007ffdde800510 R15: 00007ffdde8005f8 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 b7 91 b0 f7 e9 4c ff ff ff e8 2d 08 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d b7 55 66 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6 RAX: 9247631d38504f00 RBX: ffffffff8a204e37 RCX: 9247631d38504f00 RDX: 0000000000000001 RSI: ffffffff8a8c0420 RDI: ffffffff8adef6a0 RBP: ffffffff8c807ec0 R08: dffffc0000000000 R09: ffffed10171c6af6 R10: ffffed10171c6af6 R11: 1ffff110171c6af5 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c8bc680 R15: 1ffffffff1c3ead6 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854c590f40 CR3: 00000000795ee000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x490/0x539 init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb