rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12552/1:b..l rcu: (detected by 1, t=10502 jiffies, g=42845, q=208 ncpus=2) task:syz.2.2778 state:R running task stack:23776 pid:12552 tgid:12551 ppid:5818 task_flags:0x400140 flags:0x00024002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5855 Code: 2b 00 74 08 4c 89 f7 e8 7a bf 89 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90004e37680 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920009c6edc RCX: ffff88805e59e4e8 RDX: dffffc0000000000 RSI: ffffffff8c2ab700 RDI: ffffffff8c801c20 RBP: ffffc90004e377d0 R08: ffffffff94514847 R09: 1ffffffff28a2908 R10: dffffc0000000000 R11: fffffbfff28a2909 R12: 1ffff920009c6ed8 R13: dffffc0000000000 R14: ffffc90004e376e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] io_poll_remove_entries+0x84/0x640 io_uring/poll.c:177 __io_arm_poll_handler+0x41b/0x9d0 io_uring/poll.c:603 io_arm_poll_handler+0x7de/0xbf0 io_uring/poll.c:707 io_queue_async+0xa4/0x4e0 io_uring/io_uring.c:1925 io_handle_tw_list+0x380/0x500 io_uring/io_uring.c:1059 tctx_task_work_run+0x9a/0x370 io_uring/io_uring.c:1123 tctx_task_work+0x9a/0x100 io_uring/io_uring.c:1141 task_work_run+0x24f/0x310 kernel/task_work.c:227 get_signal+0x15d1/0x1720 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc0dd8d169 RSP: 002b:00007fbc0ec07038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000000200 RBX: 00007fbc0dfa5fa0 RCX: 00007fbc0dd8d169 RDX: 0000000000000000 RSI: 0000000000003516 RDI: 0000000000000004 RBP: 00007fbc0de0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbc0dfa5fa0 R15: 00007ffed14ffae8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g42845 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=21845 rcu: rcu_preempt kthread starved for 10502 jiffies! g42845 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12557 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller-00016-g48a5eed9ad58 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:lock_is_held_type+0x67/0x190 kernel/locking/lockdep.c:5919 Code: f1 00 00 00 65 4c 8b 2c 25 00 d5 03 00 41 83 bd ec 0a 00 00 00 0f 85 da 00 00 00 41 89 f6 49 89 ff 48 c7 04 24 00 00 00 00 9c <8f> 04 24 4c 8b 24 24 fa 48 c7 c7 40 b2 2a 8c e8 05 1b 00 00 65 ff RSP: 0000:ffffc90000007c20 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffff888025c88000 RDX: ffff888025c88000 RSI: 00000000ffffffff RDI: ffff88802a1bf300 RBP: dffffc0000000000 R08: ffffffff89fcb11b R09: fffff52000000f7c R10: dffffc0000000000 R11: fffff52000000f7c R12: 0000000000000000 R13: ffff888025c88000 R14: 00000000ffffffff R15: ffff88802a1bf300 FS: 000055555b6dd500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f428e935680 CR3: 000000007d7b6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0xcd/0xca0 net/sched/sch_taprio.c:925 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31 Code: db eb d0 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 <31> d2 e9 ef e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RSP: 0000:ffffc900048e7770 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0002d11800 RCX: ffffffff81fb89f8 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0002d11800 RBP: 0000000000000000 R08: ffffffff81fb89e1 R09: 1ffffd40005a2300 R10: dffffc0000000000 R11: fffff940005a2301 R12: ffffc900048e7940 R13: 1ffffd40005a2301 R14: ffffea0002d11808 R15: 000000000000013f instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] folio_test_readahead include/linux/page-flags.h:563 [inline] next_uptodate_folio+0x308/0x5f0 mm/filemap.c:3645 filemap_map_pages+0x12d0/0x1900 mm/filemap.c:3821 do_fault_around mm/memory.c:5361 [inline] do_read_fault mm/memory.c:5394 [inline] do_fault mm/memory.c:5537 [inline] do_pte_missing mm/memory.c:4058 [inline] handle_pte_fault mm/memory.c:5900 [inline] __handle_mm_fault+0x4acb/0x70f0 mm/memory.c:6043 handle_mm_fault+0x2c1/0x7e0 mm/memory.c:6212 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f428e935680 Code: 8b 54 24 18 64 48 2b 14 25 28 00 00 00 75 08 48 81 c4 d8 00 00 00 c3 e8 5e ad 05 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <48> 81 ec d8 00 00 00 48 89 4c 24 38 4c 89 44 24 40 4c 89 4c 24 48 RSP: 002b:00007ffc33fd7878 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 00007f428ea0f9de RSI: 0000000000000040 RDI: 00007ffc33fd7910 RBP: 00007ffc33fd78bc R08: 0000000000000000 R09: 00007f428f6dd6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000001eb R13: 000055555b6f0590 R14: 000000000003f3cc R15: 00007ffc33fd7910