====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc4-syzkaller-00356-g8f2975c2bb4c #0 Not tainted ------------------------------------------------------ syz-executor.3/3992 is trying to acquire lock: ffffffff8c0c2268 (zonelist_update_seq.seqcount){...-}-{0:0}, at: __alloc_pages+0x4a6/0x5a0 mm/page_alloc.c:5568 but task is already holding lock: ffff88802c828418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:999 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&base->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:999 __mod_timer+0x398/0xe30 kernel/time/timer.c:1072 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1676 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1701 psi_task_change+0x1bb/0x2f0 kernel/sched/psi.c:833 psi_enqueue kernel/sched/stats.h:141 [inline] enqueue_task+0x1ec/0x3a0 kernel/sched/core.c:2056 activate_task kernel/sched/core.c:2085 [inline] wake_up_new_task+0x62e/0xda0 kernel/sched/core.c:4688 kernel_clone+0x225/0x980 kernel/fork.c:2702 user_mode_thread+0xad/0xe0 kernel/fork.c:2747 rest_init+0x23/0x270 init/main.c:694 arch_call_rest_init+0xf/0x14 init/main.c:890 start_kernel+0x478/0x499 init/main.c:1145 secondary_startup_64_no_verify+0xce/0xdb -> #3 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:537 raw_spin_rq_lock kernel/sched/sched.h:1354 [inline] rq_lock kernel/sched/sched.h:1644 [inline] task_fork_fair+0x68/0x520 kernel/sched/fair.c:11608 sched_cgroup_fork+0x3cd/0x540 kernel/sched/core.c:4632 copy_process+0x4351/0x7190 kernel/fork.c:2370 kernel_clone+0xe7/0x980 kernel/fork.c:2671 user_mode_thread+0xad/0xe0 kernel/fork.c:2747 rest_init+0x23/0x270 init/main.c:694 arch_call_rest_init+0xf/0x14 init/main.c:890 start_kernel+0x478/0x499 init/main.c:1145 secondary_startup_64_no_verify+0xce/0xdb -> #2 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 try_to_wake_up+0xb2/0x20f0 kernel/sched/core.c:4076 up+0x75/0xb0 kernel/locking/semaphore.c:191 __up_console_sem+0xa4/0xc0 kernel/printk/printk.c:260 __console_unlock kernel/printk/printk.c:2651 [inline] console_unlock+0x4ca/0x600 kernel/printk/printk.c:2862 vga_remove_vgacon drivers/pci/vgaarb.c:189 [inline] vga_remove_vgacon.cold+0x99/0x9e drivers/pci/vgaarb.c:170 virtio_gpu_pci_quirk drivers/gpu/drm/virtio/virtgpu_drv.c:60 [inline] virtio_gpu_probe.cold+0xe3/0x15d drivers/gpu/drm/virtio/virtgpu_drv.c:91 virtio_dev_probe+0x577/0x870 drivers/virtio/virtio.c:305 call_driver_probe drivers/base/dd.c:560 [inline] really_probe+0x249/0xb90 drivers/base/dd.c:639 __driver_probe_device+0x1df/0x4d0 drivers/base/dd.c:778 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:808 __driver_attach+0x1d0/0x550 drivers/base/dd.c:1190 bus_for_each_dev+0x147/0x1d0 drivers/base/bus.c:301 bus_add_driver+0x4c9/0x640 drivers/base/bus.c:618 driver_register+0x220/0x3a0 drivers/base/driver.c:246 do_one_initcall+0x13d/0x780 init/main.c:1303 do_initcall_level init/main.c:1376 [inline] do_initcalls init/main.c:1392 [inline] do_basic_setup init/main.c:1411 [inline] kernel_init_freeable+0x6ff/0x788 init/main.c:1631 kernel_init+0x1a/0x1d0 init/main.c:1519 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 -> #1 ((console_sem).lock){-...}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 down_trylock+0xe/0x60 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x120 kernel/printk/printk.c:243 console_trylock kernel/printk/printk.c:2585 [inline] console_trylock_spinning kernel/printk/printk.c:1867 [inline] vprintk_emit+0x167/0x5f0 kernel/printk/printk.c:2267 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2289 build_zonelists+0x2e7/0x400 mm/page_alloc.c:6500 __build_all_zonelists+0x122/0x180 mm/page_alloc.c:6616 build_all_zonelists_init+0x35/0x12f mm/page_alloc.c:6641 build_all_zonelists+0x11f/0x140 mm/page_alloc.c:6674 start_kernel+0xb9/0x499 init/main.c:967 secondary_startup_64_no_verify+0xce/0xdb -> #0 (zonelist_update_seq.seqcount){...-}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline] read_seqbegin include/linux/seqlock.h:836 [inline] zonelist_iter_begin mm/page_alloc.c:4727 [inline] __alloc_pages_slowpath.constprop.0+0x1ae/0x23d0 mm/page_alloc.c:5049 __alloc_pages+0x4a6/0x5a0 mm/page_alloc.c:5568 __alloc_pages_node include/linux/gfp.h:223 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2570 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943 ____cache_alloc mm/slab.c:3019 [inline] ____cache_alloc mm/slab.c:3002 [inline] __do_cache_alloc mm/slab.c:3202 [inline] slab_alloc_node mm/slab.c:3250 [inline] slab_alloc mm/slab.c:3265 [inline] __kmem_cache_alloc_lru mm/slab.c:3442 [inline] kmem_cache_alloc+0x35c/0x450 mm/slab.c:3461 kmem_cache_zalloc include/linux/slab.h:679 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 __debug_object_init+0x7a/0xd10 lib/debugobjects.c:562 debug_object_init lib/debugobjects.c:617 [inline] debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:703 debug_timer_activate kernel/time/timer.c:782 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1103 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1676 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1701 queue_delayed_work include/linux/workqueue.h:518 [inline] schedule_delayed_work include/linux/workqueue.h:670 [inline] __static_key_slow_dec_deferred+0xb1/0x100 kernel/jump_label.c:289 kvm_free_lapic+0x14c/0x1a0 arch/x86/kvm/lapic.c:2319 kvm_arch_vcpu_destroy+0x130/0x330 arch/x86/kvm/x86.c:11974 kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:495 [inline] kvm_destroy_vcpus+0x113/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:515 kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:12545 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1320 [inline] kvm_put_kvm+0x4fa/0xb70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1354 kvm_vcpu_release+0x4d/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3816 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:296 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: zonelist_update_seq.seqcount --> &rq->__lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->__lock); lock(&base->lock); lock(zonelist_update_seq.seqcount); *** DEADLOCK *** 1 lock held by syz-executor.3/3992: #0: ffff88802c828418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:999 stack backtrace: CPU: 0 PID: 3992 Comm: syz-executor.3 Not tainted 6.1.0-rc4-syzkaller-00356-g8f2975c2bb4c #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+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline] read_seqbegin include/linux/seqlock.h:836 [inline] zonelist_iter_begin mm/page_alloc.c:4727 [inline] __alloc_pages_slowpath.constprop.0+0x1ae/0x23d0 mm/page_alloc.c:5049 __alloc_pages+0x4a6/0x5a0 mm/page_alloc.c:5568 __alloc_pages_node include/linux/gfp.h:223 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2570 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943 ____cache_alloc mm/slab.c:3019 [inline] ____cache_alloc mm/slab.c:3002 [inline] __do_cache_alloc mm/slab.c:3202 [inline] slab_alloc_node mm/slab.c:3250 [inline] slab_alloc mm/slab.c:3265 [inline] __kmem_cache_alloc_lru mm/slab.c:3442 [inline] kmem_cache_alloc+0x35c/0x450 mm/slab.c:3461 kmem_cache_zalloc include/linux/slab.h:679 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 __debug_object_init+0x7a/0xd10 lib/debugobjects.c:562 debug_object_init lib/debugobjects.c:617 [inline] debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:703 debug_timer_activate kernel/time/timer.c:782 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1103 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1676 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1701 queue_delayed_work include/linux/workqueue.h:518 [inline] schedule_delayed_work include/linux/workqueue.h:670 [inline] __static_key_slow_dec_deferred+0xb1/0x100 kernel/jump_label.c:289 kvm_free_lapic+0x14c/0x1a0 arch/x86/kvm/lapic.c:2319 kvm_arch_vcpu_destroy+0x130/0x330 arch/x86/kvm/x86.c:11974 kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:495 [inline] kvm_destroy_vcpus+0x113/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:515 kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:12545 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1320 [inline] kvm_put_kvm+0x4fa/0xb70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1354 kvm_vcpu_release+0x4d/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3816 __fput+0x27c/0xa90 fs/file_table.c:320 task_work_run+0x16b/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:296 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff81383d40b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffd5f0ec4e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007ff81383d40b RDX: 00007ff813400d38 RSI: ffffffffffffffff RDI: 0000000000000006 RBP: 00007ff8139ad980 R08: 0000000000000000 R09: 00007ff813400000 R10: 00007ff813400d40 R11: 0000000000000293 R12: 000000000001ffa7 R13: 00007ffd5f0ec5e0 R14: 00007ff8139abf80 R15: 0000000000000032