GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8952/2:b..l rcu: (detected by 0, t=10503 jiffies, g=21681, q=212 ncpus=2) task:syz.2.735 state:R running task stack:26080 pid:8952 tgid:8932 ppid:5824 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_is_watching+0x80/0xc0 kernel/rcu/tree.c:738 Code: 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 83 e0 01 65 ff 0d d8 49 84 7e <74> 07 5b 5d c3 cc cc cc cc e8 a2 55 8c ff 5b 5d c3 cc cc cc cc 48 RSP: 0018:ffffc9001b51f6a0 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffff8880b8637f68 RCX: ffffc9000f565000 RDX: 0000000000000000 RSI: ffffffff8bd1b3e0 RDI: ffffffff8da72be0 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000002 R12: 00000000000000b0 R13: ffffc9001b51f9c8 R14: ffffc9001b51f9c8 R15: ffffffff81d00670 rcu_read_lock include/linux/rcupdate.h:850 [inline] filemap_map_pages+0xc58/0x16b0 mm/filemap.c:3645 do_fault_around mm/memory.c:5280 [inline] do_read_fault mm/memory.c:5313 [inline] do_fault mm/memory.c:5456 [inline] do_pte_missing+0xdab/0x3e70 mm/memory.c:3979 handle_pte_fault mm/memory.c:5801 [inline] __handle_mm_fault+0x103c/0x2a40 mm/memory.c:5944 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6112 faultin_page mm/gup.c:1187 [inline] __get_user_pages+0x8d9/0x3b50 mm/gup.c:1485 populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1923 __mm_populate+0x1d6/0x380 mm/gup.c:2026 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x293/0x360 mm/util.c:585 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:542 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe1a1f80849 RSP: 002b:00007fe1a2cc0058 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe1a2146160 RCX: 00007fe1a1f80849 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007fe1a1ff3986 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe1a2146160 R15: 00007ffe2630e938 rcu: rcu_preempt kthread timer wakeup didn't happen for 10486 jiffies! g21681 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=19074 rcu: rcu_preempt kthread starved for 10487 jiffies! g21681 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27216 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-syzkaller-12113-gbcc8eda6d349 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299 Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 RSP: 0018:ffffc90000a18e28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81873798 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88805a85b340 R13: ffff8880b872cb00 R14: ffff8880b872ca00 R15: ffffffff8941c100 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f2909 CR3: 0000000031754000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] __run_hrtimer kernel/time/hrtimer.c:1742 [inline] __hrtimer_run_queues+0x873/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 18 f4 d9 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 88 66 b3 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b29c819 RDX: 0000000000000001 RSI: ffff888020ef9800 RDI: ffff888020ef9864 RBP: ffff888020ef9864 R08: 0000000000000001 R09: ffffed10170e6fed R10: ffff8880b8737f6b R11: 0000000000000000 R12: ffff8881482a5800 R13: ffffffff8ee14960 R14: 0000000000000001 R15: 0000000000000000 acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:699 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x310/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:314 common_startup_64+0x13e/0x148 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog