rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=76a4/1/0x4000000000000000 softirq=44131/44132 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=37833, q=199 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11735 Comm: syz.5.2155 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:109 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline] RIP: 0010:lock_is_held_type+0x118/0x190 kernel/locking/lockdep.c:5945 Code: 01 00 00 00 48 c7 c7 e5 a7 b5 8d e8 62 16 00 00 b8 ff ff ff ff 65 0f c1 05 d5 a3 3a 07 83 f8 01 75 44 48 c7 04 24 00 00 00 00 <9c> 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 RSP: 0018:ffffc90000a08cf8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0d646837e6c8df00 RDX: ffff888027028000 RSI: ffffffff8db5a7e5 RDI: ffffffff8be1b740 RBP: 00000000ffffffff R08: ffff88807e9a6357 R09: 0000000000000000 R10: ffff88807e9a6340 R11: ffffed100fd34c6b R12: 0000000000000046 R13: ffff888027028000 R14: ffff8880b8727ad8 R15: 0000000000000005 FS: 00007f7d832e36c0(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2ff54c CR3: 0000000092562000 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] __run_hrtimer kernel/time/hrtimer.c:1727 [inline] __hrtimer_run_queues+0x284/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_switch+0x104/0x130 kernel/kcov.c:-1 Code: e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 5b 41 5c <41> 5e 41 5f e9 d3 b6 a1 09 cc b9 05 00 00 00 48 85 c0 0f 85 4c ff RSP: 0018:ffffc9000450f560 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 000000000000064f RCX: 0000000000000007 RDX: ffffffff81f86d6b RSI: ffffffff8e1fd7e0 RDI: ffffea00012f0480 RBP: 1ffff920008a1ee3 R08: ffff888027028000 R09: 0000000000000002 R10: 0000000000000406 R11: 0000000000000002 R12: ffffea00012f0480 R13: dffffc0000000000 R14: ffffc9000450f718 R15: ffffc9000450f700 xas_retry include/linux/xarray.h:1534 [inline] next_uptodate_folio+0x6b/0x5d0 mm/filemap.c:3568 filemap_map_pages+0x1025/0x1740 mm/filemap.c:3755 do_fault_around mm/memory.c:5568 [inline] do_read_fault mm/memory.c:5601 [inline] do_fault mm/memory.c:5744 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x368a/0x5620 mm/memory.c:6232 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401 faultin_page mm/gup.c:1186 [inline] __get_user_pages+0x1af4/0x30b0 mm/gup.c:1488 populate_vma_page_range+0x26b/0x340 mm/gup.c:1926 __mm_populate+0x24c/0x380 mm/gup.c:2029 mm_populate include/linux/mm.h:3348 [inline] vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7d8238e929 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:00007f7d832e3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f7d825b5fa0 RCX: 00007f7d8238e929 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f7d82410b39 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7d825b5fa0 R15: 00007fff54060ea8 rcu: rcu_preempt kthread starved for 10498 jiffies! g37833 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 11739 Comm: syz.4.2156 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 60 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 0b 74 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 f0 73 0b RSP: 0018:ffffc9001047fa60 EFLAGS: 00000246 RAX: ffffffff81b4e790 RBX: ffff8880b863b040 RCX: 0000000000080000 RDX: ffffc9000ce29000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9001047fbc0 R08: ffffffff8f9fdef7 R09: 1ffffffff1f3fbde R10: dffffc0000000000 R11: fffffbfff1f3fbdf R12: 1ffff110170e7f2d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873f968 FS: 00007fd6773836c0(0000) GS:ffff888125c85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd677382f98 CR3: 0000000084baa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline] smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_slow_inc_cpuslocked+0x80/0xf0 kernel/jump_label.c:168 static_key_slow_inc+0x1a/0x30 kernel/jump_label.c:191 io_uring_create+0x1e4/0xb60 io_uring/io_uring.c:3691 io_uring_setup io_uring/io_uring.c:3830 [inline] __do_sys_io_uring_setup io_uring/io_uring.c:3864 [inline] __se_sys_io_uring_setup+0x264/0x270 io_uring/io_uring.c:3855 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd67658e929 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:00007fd677382fc8 EFLAGS: 00000202 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00007fd6767b5fa0 RCX: 00007fd67658e929 RDX: 0000200000000540 RSI: 0000200000000480 RDI: 000000000000081f RBP: 0000200000000480 R08: 0000000000000000 R09: 0000200000000540 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00002000000000c0 R14: 000000000000081f R15: 0000200000000540