GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=b13c/1/0x4000000000000000 softirq=27595/27596 fqs=1 rcu: (detected by 1, t=10505 jiffies, g=20069, q=196 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7629 Comm: syz.5.576 Not tainted 6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1763 [inline] RIP: 0010:__hrtimer_run_queues+0x535/0xc60 kernel/time/hrtimer.c:1825 Code: 41 0f b6 44 1d 00 84 c0 0f 85 74 03 00 00 41 c7 07 01 00 00 00 4c 89 e7 4d 89 f3 2e e8 d4 79 c3 09 41 89 c6 41 0f b6 44 1d 00 <84> c0 0f 85 6e 03 00 00 41 c7 07 00 00 00 00 48 8b 5c 24 18 0f 1f RSP: 0018:ffffc90000007d40 EFLAGS: 00000082 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: dbe54e066ebe3100 RDX: 0000000000000004 RSI: ffffffff8db865be RDI: ffff8880271a5a00 RBP: ffffc90000007e90 R08: ffff88807badf15f R09: 1ffff1100f75be2b R10: dffffc0000000000 R11: ffffed100f75be2c R12: ffff88807badf340 R13: 1ffff11004e34c9b R14: 0000000000000001 R15: ffff8880271a64d8 FS: 000055555c8a8500(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30e1fffc CR3: 000000007fb9d000 CR4: 0000000000350ef0 Call Trace: 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:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf6e/0x12d0 kernel/smp.c:885 Code: 89 ee 83 e6 01 31 ff e8 d0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7b 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 60 74 0b 00 eb e5 44 89 RSP: 0018:ffffc9000bb67980 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b863b1c0 RCX: ffff8880271a5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000bb67ae0 R08: ffffffff8fa1f3f7 R09: 1ffffffff1f43e7e R10: dffffc0000000000 R11: fffffbfff1f43e7f R12: 1ffff110170e7f5d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873fae8 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_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 tracepoint_remove_func kernel/tracepoint.c:370 [inline] tracepoint_probe_unregister+0x80e/0x9b0 kernel/tracepoint.c:504 bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3635 bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3157 bpf_link_put_direct kernel/bpf/syscall.c:3200 [inline] bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3207 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f73fcf8e929 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:00007ffeb0fd7818 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000002aaf3 RCX: 00007f73fcf8e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f73fd1b7ba0 R08: 0000000000000001 R09: 00000004b0fd7b0f R10: 00007f73fce00000 R11: 0000000000000246 R12: 00007f73fd1b5fac R13: 00007f73fd1b5fa0 R14: ffffffffffffffff R15: 00007ffeb0fd7930 rcu: rcu_preempt kthread starved for 10500 jiffies! g20069 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 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+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/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: 1 UID: 0 PID: 7632 Comm: syz.2.577 Not tainted 6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #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+0xf6e/0x12d0 kernel/smp.c:885 Code: 89 ee 83 e6 01 31 ff e8 d0 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7b 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 60 74 0b 00 eb e5 44 89 RSP: 0018:ffffc9000bbef4a0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b873b1c0 RCX: ffff8880271a3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000bbef600 R08: ffffffff8fa1f3f7 R09: 1ffffffff1f43e7e R10: dffffc0000000000 R11: fffffbfff1f43e7f R12: 1ffff110170c8385 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c28 FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30d1cff8 CR3: 000000005e91d000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 exit_mmap+0x44c/0xb50 mm/mmap.c:1297 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb17a58e929 Code: Unable to access opcode bytes at 0x7fb17a58e8ff. RSP: 002b:00007fb17b3ac0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fb17a7b5fa8 RCX: 00007fb17a58e929 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fb17a7b5fac RBP: 00007fb17a7b5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb17a7b5fac R13: 0000000000000000 R14: 00007ffcc161c790 R15: 00007ffcc161c878