rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=ab8c/1/0x4000000000000000 softirq=18741/18751 fqs=3 rcu: (detected by 1, t=10506 jiffies, g=10941, q=94 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5819 Comm: syz-executor Not tainted 6.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x40/0x3c40 kernel/locking/lockdep.c:5079 Code: 81 ec f0 00 00 00 48 8b 84 24 28 01 00 00 44 89 04 24 48 c7 84 24 90 00 00 00 b3 8a b5 41 48 c7 84 24 98 00 00 00 e5 38 98 8d <48> c7 84 24 a0 00 00 00 f0 60 96 81 48 89 44 24 10 48 8d 84 24 90 RSP: 0018:ffffc90000007be8 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b862c698 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625917 R11: 0000000000000004 R12: ffff8880b862c698 R13: ffff8880b862c698 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555557736500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000400000002320 CR3: 0000000060754000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1805 [inline] __hrtimer_run_queues+0x2be/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 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:lock_acquire.part.0+0x155/0x380 kernel/locking/lockdep.c:5816 Code: b8 ff ff ff ff 65 0f c1 05 00 d9 6b 7e 83 f8 01 0f 85 d0 01 00 00 9c 58 f6 c4 02 0f 85 e5 01 00 00 48 85 ed 0f 85 b6 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00 00 00 00 48 c7 RSP: 0018:ffffc90003ddf7d0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 1ffff920007bbefb RCX: 00000000753d0d3c RDX: 0000000000000001 RSI: ffffffff8b6cf060 RDI: ffffffff8bd359e0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000003 R12: 0000000000000000 R13: ffffffff8e1bccc0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] percpu_ref_get_many include/linux/percpu-refcount.h:202 [inline] percpu_ref_get include/linux/percpu-refcount.h:222 [inline] obj_cgroup_get include/linux/memcontrol.h:764 [inline] __memcg_slab_post_alloc_hook+0x3de/0x9b0 mm/memcontrol.c:3001 memcg_slab_post_alloc_hook mm/slub.c:2152 [inline] slab_post_alloc_hook mm/slub.c:4125 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x366/0x3d0 mm/slub.c:4171 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0xe1/0x5e0 mm/rmap.c:288 anon_vma_fork+0x7a/0x620 mm/rmap.c:351 dup_mmap kernel/fork.c:711 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm kernel/fork.c:1752 [inline] copy_process+0x82c8/0x8c50 kernel/fork.c:2403 kernel_clone+0xfd/0x960 kernel/fork.c:2815 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958 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: 0033:0x7f0b967839d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffccc5ede18 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0b967839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555577367d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000021c85 R15: 00007ffccc5edfb0 rcu: rcu_preempt kthread starved for 10485 jiffies! g10941 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:28208 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 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: CPU: 1 UID: 0 PID: 6807 Comm: syz.4.261 Not tainted 6.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4c6/0x12c0 kernel/smp.c:885 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 fc 4c 89 fd 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 7c 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 e8 0b 00 00 8b 43 08 31 RSP: 0018:ffffc9001c4074c0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8646a00 RCX: ffffffff81add36a RDX: ffff888032474880 RSI: ffffffff81add344 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: ffffed10170c8d41 R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3100c9 CR3: 000000007f852000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x271/0x4a0 arch/x86/mm/tlb.c:1054 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:481 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:471 [inline] zap_pte_range mm/memory.c:1769 [inline] zap_pmd_range mm/memory.c:1834 [inline] zap_pud_range mm/memory.c:1863 [inline] zap_p4d_range mm/memory.c:1884 [inline] unmap_page_range+0x1f5b/0x4390 mm/memory.c:1905 unmap_single_vma+0x194/0x2b0 mm/memory.c:1951 unmap_vmas+0x22f/0x490 mm/memory.c:1995 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x24ed/0x26c0 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6fef78d169 Code: Unable to access opcode bytes at 0x7f6fef78d13f. RSP: 002b:00007f6ff06720e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6fef9a5fa8 RCX: 00007f6fef78d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6fef9a5fa8 RBP: 00007f6fef9a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6fef9a5fac R13: 0000000000000000 R14: 00007fffceaa3390 R15: 00007fffceaa3478