====================================================== WARNING: possible circular locking dependency detected 6.4.0-rc2-next-20230515-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/13583 is trying to acquire lock: ffff88813fffeba0 (&pgdat->kswapd_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 but task is already holding lock: ffff8880b992b898 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] ffff8880b992b898 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xa30 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+0xea/0xbd0 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+0xbdf/0x27d0 kernel/sched/core.c:7781 _sched_setscheduler kernel/sched/core.c:7828 [inline] sched_setscheduler_nocheck kernel/sched/core.c:7875 [inline] sched_set_fifo+0xb1/0x110 kernel/sched/core.c:7899 drm_vblank_worker_init+0x197/0x220 drivers/gpu/drm/drm_vblank_work.c:263 drm_vblank_init+0x128/0x340 drivers/gpu/drm/drm_vblank.c:551 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:191 [inline] vkms_init+0x3a8/0x770 drivers/gpu/drm/vkms/vkms_drv.c:234 do_one_initcall+0x102/0x540 init/main.c:1246 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5a4/0x890 init/main.c:1571 kernel_init+0x1e/0x2c0 init/main.c:1462 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:9536 set_rq_online kernel/sched/core.c:9528 [inline] sched_cpu_activate+0x216/0x440 kernel/sched/core.c:9644 cpuhp_invoke_callback+0x3b5/0x9a0 kernel/cpu.c:192 cpuhp_thread_fun+0x47f/0x700 kernel/cpu.c:815 smpboot_thread_fn+0x659/0x9f0 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:12097 sched_cgroup_fork+0x3d1/0x540 kernel/sched/core.c:4777 copy_process+0x4b8a/0x7600 kernel/fork.c:2614 kernel_clone+0xeb/0x890 kernel/fork.c:2914 user_mode_thread+0xb1/0xf0 kernel/fork.c:2992 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/0x1a50 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:3094 [inline] get_page_from_freelist+0x702/0x2a80 mm/page_alloc.c:3536 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4805 __folio_alloc+0x16/0x40 mm/page_alloc.c:4837 vma_alloc_folio+0x155/0x850 mm/mempolicy.c:2240 do_anonymous_page mm/memory.c:4088 [inline] do_pte_missing mm/memory.c:3648 [inline] handle_pte_fault mm/memory.c:4950 [inline] __handle_mm_fault+0x2263/0x4170 mm/memory.c:5092 handle_mm_fault+0x2af/0x9f0 mm/memory.c:5246 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:3113 [inline] check_prevs_add kernel/locking/lockdep.c:3232 [inline] validate_chain kernel/locking/lockdep.c:3847 [inline] __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088 lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5705 __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 rmqueue mm/page_alloc.c:3094 [inline] get_page_from_freelist+0x702/0x2a80 mm/page_alloc.c:3536 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4805 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x28e/0x380 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:606 [inline] debug_object_activate+0x12d/0x4f0 lib/debugobjects.c:704 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+0x8d9/0xa30 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 lockdep_enabled kernel/locking/lockdep.c:116 [inline] lock_release+0xcf/0x670 kernel/locking/lockdep.c:5718 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_unlock+0x16/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:390 [inline] rmqueue_pcplist mm/page_alloc.c:3037 [inline] rmqueue mm/page_alloc.c:3079 [inline] get_page_from_freelist+0x547/0x2a80 mm/page_alloc.c:3536 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4805 __folio_alloc+0x16/0x40 mm/page_alloc.c:4837 vma_alloc_folio+0x155/0x850 mm/mempolicy.c:2240 shmem_alloc_folio+0x119/0x1e0 mm/shmem.c:1594 shmem_alloc_and_acct_folio+0x15e/0x5d0 mm/shmem.c:1618 shmem_get_folio_gfp+0x9cc/0x1a80 mm/shmem.c:1963 shmem_get_folio mm/shmem.c:2094 [inline] shmem_write_begin+0x14a/0x380 mm/shmem.c:2588 generic_perform_write+0x256/0x570 mm/filemap.c:3896 __generic_file_write_iter+0x2ae/0x500 mm/filemap.c:4024 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4056 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x945/0xd50 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd 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 syz-executor.0/13583: #0: ffff888014272460 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:637 #1: ffff8880a4dc4de8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:775 [inline] #1: ffff8880a4dc4de8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: generic_file_write_iter+0x92/0x350 mm/filemap.c:4053 #2: ffff8880b9943618 (&pcp->lock){+.+.}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #2: ffff8880b9943618 (&pcp->lock){+.+.}-{2:2}, at: rmqueue_pcplist mm/page_alloc.c:3023 [inline] #2: ffff8880b9943618 (&pcp->lock){+.+.}-{2:2}, at: rmqueue mm/page_alloc.c:3079 [inline] #2: ffff8880b9943618 (&pcp->lock){+.+.}-{2:2}, at: get_page_from_freelist+0x4c7/0x2a80 mm/page_alloc.c:3536 #3: ffff8880b992b898 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline] #3: ffff8880b992b898 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x23e/0xa30 kernel/time/hrtimer.c:1749 #4: ffffffff8d105400 (fill_pool_map-wait-type-override){+.+.}-{3:3}, at: debug_object_activate+0xf7/0x4f0 lib/debugobjects.c:754 stack backtrace: CPU: 1 PID: 13583 Comm: syz-executor.0 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 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:3113 [inline] check_prevs_add kernel/locking/lockdep.c:3232 [inline] validate_chain kernel/locking/lockdep.c:3847 [inline] __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088 lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5705 __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 rmqueue mm/page_alloc.c:3094 [inline] get_page_from_freelist+0x702/0x2a80 mm/page_alloc.c:3536 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4805 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x28e/0x380 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:606 [inline] debug_object_activate+0x12d/0x4f0 lib/debugobjects.c:704 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+0x8d9/0xa30 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:lockdep_enabled kernel/locking/lockdep.c:116 [inline] RIP: 0010:lock_release+0xcf/0x670 kernel/locking/lockdep.c:5718 Code: 48 0f a3 1d 73 2b 15 0d 0f 82 43 04 00 00 48 c7 c3 f0 2b 7b 8e 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 <48> 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 bf 04 00 00 44 RSP: 0018:ffffc9000cf973e0 EFLAGS: 00000a06 RAX: dffffc0000000000 RBX: ffffffff8e7b2bf0 RCX: ffffffff8165cb55 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffffff8c13ea08 RBP: 1ffff920019f2e7e R08: 0000000000000000 R09: fffffbfff1cf5eda R10: ffffffff8e7af6d7 R11: 0000000000000000 R12: ffff8880b9943618 R13: 0000000000000001 R14: 0000000000000003 R15: dffffc0000000000 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_unlock+0x16/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:390 [inline] rmqueue_pcplist mm/page_alloc.c:3037 [inline] rmqueue mm/page_alloc.c:3079 [inline] get_page_from_freelist+0x547/0x2a80 mm/page_alloc.c:3536 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4805 __folio_alloc+0x16/0x40 mm/page_alloc.c:4837 vma_alloc_folio+0x155/0x850 mm/mempolicy.c:2240 shmem_alloc_folio+0x119/0x1e0 mm/shmem.c:1594 shmem_alloc_and_acct_folio+0x15e/0x5d0 mm/shmem.c:1618 shmem_get_folio_gfp+0x9cc/0x1a80 mm/shmem.c:1963 shmem_get_folio mm/shmem.c:2094 [inline] shmem_write_begin+0x14a/0x380 mm/shmem.c:2588 generic_perform_write+0x256/0x570 mm/filemap.c:3896 __generic_file_write_iter+0x2ae/0x500 mm/filemap.c:4024 generic_file_write_iter+0xe3/0x350 mm/filemap.c:4056 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x945/0xd50 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f26a943deef Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48 RSP: 002b:00007f26aa279f10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f26a943deef RDX: 0000000001000000 RSI: 00007f269fbff000 RDI: 0000000000000003 RBP: 00007f269fbff000 R08: 0000000000000000 R09: 00000000000050e9 R10: 0000000001000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f26aa279fdc R14: 00007f26aa279fe0 R15: 0000000020005182 ---------------- Code disassembly (best guess): 0: 48 0f a3 1d 73 2b 15 bt %rbx,0xd152b73(%rip) # 0xd152b7b 7: 0d 8: 0f 82 43 04 00 00 jb 0x451 e: 48 c7 c3 f0 2b 7b 8e mov $0xffffffff8e7b2bf0,%rbx 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 da mov %rbx,%rdx 22: 48 c1 ea 03 shr $0x3,%rdx 26: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx * 2a: 48 89 d8 mov %rbx,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 d0 cmp %dl,%al 35: 7c 08 jl 0x3f 37: 84 d2 test %dl,%dl 39: 0f 85 bf 04 00 00 jne 0x4fe 3f: 44 rex.R