====================================================== WARNING: possible circular locking dependency detected 6.4.0-rc3-syzkaller-00004-g421ca22e3138 #0 Not tainted ------------------------------------------------------ kswapd0/112 is trying to acquire lock: ffff88807ffdaba0 (&pgdat->kswapd_wait){-...}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 but task is already holding lock: ffff88802c72b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] ffff88802c72b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xbe0 kernel/time/hrtimer.c:1749 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (hrtimer_bases.lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] hrtimer_start_range_ns+0xe9/0xd80 kernel/time/hrtimer.c:1296 hrtimer_start_expires include/linux/hrtimer.h:432 [inline] do_start_rt_bandwidth kernel/sched/rt.c:116 [inline] start_rt_bandwidth kernel/sched/rt.c:127 [inline] inc_rt_group kernel/sched/rt.c:1241 [inline] inc_rt_tasks kernel/sched/rt.c:1285 [inline] __enqueue_rt_entity kernel/sched/rt.c:1461 [inline] enqueue_rt_entity kernel/sched/rt.c:1510 [inline] enqueue_task_rt+0xa86/0xfc0 kernel/sched/rt.c:1545 enqueue_task+0xad/0x330 kernel/sched/core.c:2082 __sched_setscheduler.constprop.0+0xb89/0x25d0 kernel/sched/core.c:7774 _sched_setscheduler kernel/sched/core.c:7820 [inline] sched_setscheduler_nocheck kernel/sched/core.c:7867 [inline] sched_set_fifo+0xb1/0x110 kernel/sched/core.c:7891 irq_thread+0xe3/0x540 kernel/irq/manage.c:1302 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #3 (&rt_b->rt_runtime_lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 __enable_runtime kernel/sched/rt.c:876 [inline] rq_online_rt+0xb3/0x3b0 kernel/sched/rt.c:2485 set_rq_online.part.0+0xf9/0x140 kernel/sched/core.c:9541 set_rq_online kernel/sched/core.c:9533 [inline] sched_cpu_activate+0x216/0x440 kernel/sched/core.c:9649 cpuhp_invoke_callback+0x645/0xeb0 kernel/cpu.c:192 cpuhp_thread_fun+0x47f/0x700 kernel/cpu.c:815 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x34/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1366 [inline] rq_lock kernel/sched/sched.h:1653 [inline] task_fork_fair+0x74/0x4f0 kernel/sched/fair.c:12095 sched_cgroup_fork+0x3d1/0x540 kernel/sched/core.c:4777 copy_process+0x4b8a/0x7600 kernel/fork.c:2618 kernel_clone+0xeb/0x890 kernel/fork.c:2918 user_mode_thread+0xb1/0xf0 kernel/fork.c:2996 rest_init+0x27/0x2b0 init/main.c:700 arch_call_rest_init+0x13/0x30 init/main.c:834 start_kernel+0x3b6/0x490 init/main.c:1088 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0xf4/0xfb -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 try_to_wake_up+0xab/0x1c40 kernel/sched/core.c:4191 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:419 __wake_up_common+0x147/0x650 kernel/sched/wait.c:107 __wake_up_common_lock+0xd4/0x140 kernel/sched/wait.c:138 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x6c5/0x2c00 mm/page_alloc.c:3499 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768 __folio_alloc+0x16/0x40 mm/page_alloc.c:4800 vma_alloc_folio+0x155/0x890 mm/mempolicy.c:2240 do_anonymous_page mm/memory.c:4085 [inline] do_pte_missing mm/memory.c:3645 [inline] handle_pte_fault mm/memory.c:4947 [inline] __handle_mm_fault+0x224c/0x41c0 mm/memory.c:5089 handle_mm_fault+0x2af/0x9f0 mm/memory.c:5243 do_user_addr_fault+0x2ca/0x1210 arch/x86/mm/fault.c:1349 handle_page_fault arch/x86/mm/fault.c:1534 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1590 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 -> #0 (&pgdat->kswapd_wait){-...}-{2:2}: check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 __nr_to_section include/linux/mmzone.h:1837 [inline] __pfn_to_section include/linux/mmzone.h:1945 [inline] pfn_valid include/linux/mmzone.h:1996 [inline] pfn_valid include/linux/mmzone.h:1981 [inline] get_pte_pfn+0x27c/0x400 mm/vmscan.c:3925 walk_pte_range mm/vmscan.c:4013 [inline] walk_pmd_range mm/vmscan.c:4205 [inline] walk_pud_range+0xa0d/0x1930 mm/vmscan.c:4241 walk_p4d_range mm/pagewalk.c:233 [inline] walk_pgd_range+0x252/0x1640 mm/pagewalk.c:277 __walk_page_range+0x65a/0x790 mm/pagewalk.c:379 walk_page_range+0x311/0x4a0 mm/pagewalk.c:477 walk_mm mm/vmscan.c:4289 [inline] try_to_inc_max_seq.constprop.0+0x1239/0x2270 mm/vmscan.c:4514 get_nr_to_scan mm/vmscan.c:5304 [inline] try_to_shrink_lruvec+0x974/0xb90 mm/vmscan.c:5330 shrink_one+0x462/0x710 mm/vmscan.c:5378 shrink_many mm/vmscan.c:5430 [inline] lru_gen_shrink_node mm/vmscan.c:5547 [inline] shrink_node+0x1fd5/0x3500 mm/vmscan.c:6488 kswapd_shrink_node mm/vmscan.c:7288 [inline] balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7478 kswapd+0x677/0xd60 mm/vmscan.c:7738 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(&rt_b->rt_runtime_lock); lock(hrtimer_bases.lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 5 locks held by kswapd0/112: #0: ffffffff8c8eff80 (fs_reclaim){+.+.}-{0:0}, at: set_task_reclaim_state mm/vmscan.c:528 [inline] #0: ffffffff8c8eff80 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x170/0x1ac0 mm/vmscan.c:7364 #1: ffffffff8c799040 (rcu_read_lock){....}-{1:2}, at: walk_mm mm/vmscan.c:4280 [inline] #1: ffffffff8c799040 (rcu_read_lock){....}-{1:2}, at: try_to_inc_max_seq.constprop.0+0xee6/0x2270 mm/vmscan.c:4514 #2: ffff88801be74968 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:161 [inline] #2: ffff88801be74968 (&mm->mmap_lock){++++}-{3:3}, at: walk_mm mm/vmscan.c:4288 [inline] #2: ffff88801be74968 (&mm->mmap_lock){++++}-{3:3}, at: try_to_inc_max_seq.constprop.0+0xffc/0x2270 mm/vmscan.c:4514 #3: ffff88801e78fd98 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #3: ffff88801e78fd98 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: walk_pte_range mm/vmscan.c:3999 [inline] #3: ffff88801e78fd98 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: walk_pmd_range mm/vmscan.c:4205 [inline] #3: ffff88801e78fd98 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: walk_pud_range+0x890/0x1930 mm/vmscan.c:4241 #4: ffff88802c72b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] #4: ffff88802c72b858 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xbe0 kernel/time/hrtimer.c:1749 stack backtrace: CPU: 1 PID: 112 Comm: kswapd0 Not tainted 6.4.0-rc3-syzkaller-00004-g421ca22e3138 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2188 check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7798 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline] debug_activate kernel/time/hrtimer.c:475 [inline] enqueue_hrtimer+0x27/0x320 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xa5b/0xbe0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x7b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x14a/0x430 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__nr_to_section include/linux/mmzone.h:1837 [inline] RIP: 0010:__pfn_to_section include/linux/mmzone.h:1945 [inline] RIP: 0010:pfn_valid include/linux/mmzone.h:1996 [inline] RIP: 0010:pfn_valid include/linux/mmzone.h:1981 [inline] RIP: 0010:get_pte_pfn+0x27c/0x400 mm/vmscan.c:3925 Code: 00 e8 c8 2c ce ff 4a 8d 6c ed 00 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 6a 01 00 00 48 8b 6d 00 <48> 85 ed 0f 84 b8 00 00 00 e8 96 2c ce ff 83 e3 7f 48 c1 e3 05 48 RSP: 0018:ffffc90000e4f150 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 000000000000000f RCX: 0000000000000000 RDX: 1ffff1100fff9c00 RSI: ffffffff81b61608 RDI: 0000000000000007 RBP: ffff88803fff9000 R08: 0000000000000007 R09: 000000000007ffff R10: 000000000000000f R11: 0000000000000000 R12: 000000000007fe45 R13: 0000000000000000 R14: 1ffff920001c9e2a R15: 0000000001034000 walk_pte_range mm/vmscan.c:4013 [inline] walk_pmd_range mm/vmscan.c:4205 [inline] walk_pud_range+0xa0d/0x1930 mm/vmscan.c:4241 walk_p4d_range mm/pagewalk.c:233 [inline] walk_pgd_range+0x252/0x1640 mm/pagewalk.c:277 __walk_page_range+0x65a/0x790 mm/pagewalk.c:379 walk_page_range+0x311/0x4a0 mm/pagewalk.c:477 walk_mm mm/vmscan.c:4289 [inline] try_to_inc_max_seq.constprop.0+0x1239/0x2270 mm/vmscan.c:4514 get_nr_to_scan mm/vmscan.c:5304 [inline] try_to_shrink_lruvec+0x974/0xb90 mm/vmscan.c:5330 shrink_one+0x462/0x710 mm/vmscan.c:5378 shrink_many mm/vmscan.c:5430 [inline] lru_gen_shrink_node mm/vmscan.c:5547 [inline] shrink_node+0x1fd5/0x3500 mm/vmscan.c:6488 kswapd_shrink_node mm/vmscan.c:7288 [inline] balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7478 kswapd+0x677/0xd60 mm/vmscan.c:7738 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 ---------------- Code disassembly (best guess): 0: 00 e8 add %ch,%al 2: c8 2c ce ff enterq $0xce2c,$0xff 6: 4a 8d 6c ed 00 lea 0x0(%rbp,%r13,8),%rbp b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 12: fc ff df 15: 48 89 ea mov %rbp,%rdx 18: 48 c1 ea 03 shr $0x3,%rdx 1c: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 20: 0f 85 6a 01 00 00 jne 0x190 26: 48 8b 6d 00 mov 0x0(%rbp),%rbp * 2a: 48 85 ed test %rbp,%rbp <-- trapping instruction 2d: 0f 84 b8 00 00 00 je 0xeb 33: e8 96 2c ce ff callq 0xffce2cce 38: 83 e3 7f and $0x7f,%ebx 3b: 48 c1 e3 05 shl $0x5,%rbx 3f: 48 rex.W