rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=3d84/1/0x4000000000000000 softirq=52286/52287 fqs=2 rcu: (detected by 1, t=10506 jiffies, g=48193, q=210 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12593 Comm: syz.1.2165 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:153 [inline] RIP: 0010:lock_release+0x29a/0x3e0 kernel/locking/lockdep.c:5892 Code: c7 eb 1b 9d 8d e8 26 87 ae 09 b8 ff ff ff ff 65 0f c1 05 f9 5a f4 10 83 f8 01 75 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b RSP: 0018:ffffc90000007bf8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000006 RCX: 679e4d977faea000 RDX: 0000000000000001 RSI: ffffffff8d9d1beb RDI: ffffffff8bc077e0 RBP: ffff888033a58b58 R08: ffff88805825a487 R09: 1ffff1100b04b490 R10: dffffc0000000000 R11: ffffed100b04b491 R12: 0000000000000001 R13: 0000000000000001 R14: ffff888076588300 R15: ffff888033a58000 FS: 00007f715e3846c0(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4ada7e7dac CR3: 0000000029540000 CR4: 0000000000350ef0 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:986 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_save_alloc_info+0x3e/0x50 mm/kasan/generic.c:573 Code: 0f 94 c1 49 01 c6 0f 94 c0 08 c8 74 09 5b 41 5e e9 32 07 eb fe cc 89 d3 ba 10 00 00 00 4c 89 f7 31 f6 e8 85 4c 26 09 4c 89 f7 <89> de 5b 41 5e e9 e8 cd ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 RSP: 0018:ffffc900044a7850 EFLAGS: 00000246 RAX: ffff888058103de0 RBX: 0000000000400cc0 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff888058103de0 RBP: 0000000000400cc0 R08: dffffc0000000000 R09: ffff888058103de0 R10: 000000000000000a R11: ffffffff81abbce0 R12: 0000000000030600 R13: 0000000000000020 R14: ffff888058103de0 R15: 0000000000000020 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5725 kmalloc_noprof include/linux/slab.h:957 [inline] io_add_buffers io_uring/kbuf.c:524 [inline] __io_manage_buffers_legacy io_uring/kbuf.c:566 [inline] io_manage_buffers_legacy+0x32e/0xba0 io_uring/kbuf.c:579 __io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1824 io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1847 io_queue_sqe io_uring/io_uring.c:2074 [inline] io_submit_sqe io_uring/io_uring.c:2334 [inline] io_submit_sqes+0xa54/0x1e60 io_uring/io_uring.c:2447 __do_sys_io_uring_enter io_uring/io_uring.c:3514 [inline] __se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3453 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f715d58eec9 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:00007f715e384038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007f715d7e5fa0 RCX: 00007f715d58eec9 RDX: 0000000000000000 RSI: 00000000000047fa RDI: 0000000000000003 RBP: 00007f715d611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f715d7e6038 R14: 00007f715d7e5fa0 R15: 00007ffffc056008 rcu: rcu_preempt kthread starved for 10495 jiffies! g48193 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:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 9689 Comm: kworker/u8:33 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 96 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 41 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 25 6f RSP: 0018:ffffc90003d7f640 EFLAGS: 00000293 RAX: ffffffff81b424db RBX: 1ffff110170c8441 RCX: ffff888026b50000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003d7f7c0 R08: ffffffff8f9e1177 R09: 1ffffffff1f3c22e R10: dffffc0000000000 R11: fffffbfff1f3c22f R12: ffff8880b8642208 R13: dffffc0000000000 R14: ffff8880b873b240 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125e0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff9d4d156c0 CR3: 000000000df38000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:852 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245