====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/10900 is trying to acquire lock: ffffffff8c7d6b20 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x0/0x30 mm/page_alloc.c:4210 but task is already holding lock: ffff8880b9d4d0c8 (lock#2){-.-.}-{2:2}, at: local_lock_acquire+0x7/0x130 include/linux/local_lock_internal.h:41 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#2){-.-.}-{2:2}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 local_lock_acquire+0x23/0x130 include/linux/local_lock_internal.h:42 free_unref_page+0x242/0x550 mm/page_alloc.c:3427 mm_free_pgd kernel/fork.c:636 [inline] __mmdrop+0xae/0x3f0 kernel/fork.c:687 mmdrop include/linux/sched/mm.h:49 [inline] finish_task_switch+0x221/0x630 kernel/sched/core.c:4582 context_switch kernel/sched/core.c:4686 [inline] __schedule+0xc0f/0x11f0 kernel/sched/core.c:5940 preempt_schedule_irq+0xe3/0x190 kernel/sched/core.c:6328 irqentry_exit+0x56/0x90 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_release+0x0/0x7b0 kernel/locking/lockdep.c:3287 might_alloc include/linux/sched/mm.h:198 [inline] slab_pre_alloc_hook mm/slab.h:485 [inline] slab_alloc_node mm/slub.c:2902 [inline] slab_alloc mm/slub.c:2989 [inline] kmem_cache_alloc+0x3a/0x340 mm/slub.c:2994 anon_vma_chain_alloc mm/rmap.c:136 [inline] __anon_vma_prepare+0x66/0x480 mm/rmap.c:190 anon_vma_prepare include/linux/rmap.h:149 [inline] wp_page_copy+0x1469/0x2180 mm/memory.c:2994 handle_pte_fault mm/memory.c:4567 [inline] __handle_mm_fault mm/memory.c:4684 [inline] handle_mm_fault+0x1dc5/0x2500 mm/memory.c:4782 do_user_addr_fault+0x8ce/0x10c0 arch/x86/mm/fault.c:1390 handle_page_fault arch/x86/mm/fault.c:1475 [inline] exc_page_fault+0xa1/0x1e0 arch/x86/mm/fault.c:1531 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:91 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:200 [inline] extract_crng_user drivers/char/random.c:1074 [inline] urandom_read_nowarn+0x295/0x3d0 drivers/char/random.c:1811 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #1 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 fs_reclaim_acquire+0x79/0xf0 mm/page_alloc.c:4569 might_alloc include/linux/sched/mm.h:198 [inline] slab_pre_alloc_hook mm/slab.h:485 [inline] slab_alloc_node mm/slub.c:2902 [inline] slab_alloc mm/slub.c:2989 [inline] kmem_cache_alloc_trace+0x39/0x340 mm/slub.c:3006 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] alloc_workqueue_attrs kernel/workqueue.c:3365 [inline] wq_numa_init+0xb1/0x449 kernel/workqueue.c:5899 workqueue_init+0x18/0x7c7 kernel/workqueue.c:6031 kernel_init_freeable+0x3bf/0x57e init/main.c:1577 kernel_init+0x19/0x2a0 init/main.c:1485 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4552 fs_reclaim_acquire+0x59/0xf0 mm/page_alloc.c:4566 prepare_alloc_pages+0x151/0x5a0 mm/page_alloc.c:5164 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x75/0x80 mm/vmalloc.c:3085 allocate_partitions block/partitions/core.c:106 [inline] check_partition block/partitions/core.c:128 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x4d9/0x1690 block/partitions/core.c:697 loop_reread_partitions drivers/block/loop.c:652 [inline] loop_set_status+0x6b1/0x8e0 drivers/block/loop.c:1510 lo_ioctl+0xca2/0x23b0 drivers/block/loop.c:1620 blkdev_ioctl+0x332/0x690 block/ioctl.c:585 block_ioctl+0xae/0xf0 fs/block_dev.c:1602 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: fs_reclaim --> mmu_notifier_invalidate_range_start --> lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#2); lock(mmu_notifier_invalidate_range_start); lock(lock#2); lock(fs_reclaim); *** DEADLOCK *** 2 locks held by syz-executor.4/10900: #0: ffff88801ec88518 (&disk->open_mutex){+.+.}-{3:3}, at: loop_reread_partitions drivers/block/loop.c:651 [inline] #0: ffff88801ec88518 (&disk->open_mutex){+.+.}-{3:3}, at: loop_set_status+0x698/0x8e0 drivers/block/loop.c:1510 #1: ffff8880b9d4d0c8 (lock#2){-.-.}-{2:2}, at: local_lock_acquire+0x7/0x130 include/linux/local_lock_internal.h:41 stack backtrace: CPU: 1 PID: 10900 Comm: syz-executor.4 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2009 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add+0x4f9/0x5b30 kernel/locking/lockdep.c:3174 validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x4476/0x6100 kernel/locking/lockdep.c:5015 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4552 fs_reclaim_acquire+0x59/0xf0 mm/page_alloc.c:4566 prepare_alloc_pages+0x151/0x5a0 mm/page_alloc.c:5164 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x75/0x80 mm/vmalloc.c:3085 allocate_partitions block/partitions/core.c:106 [inline] check_partition block/partitions/core.c:128 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x4d9/0x1690 block/partitions/core.c:697 loop_reread_partitions drivers/block/loop.c:652 [inline] loop_set_status+0x6b1/0x8e0 drivers/block/loop.c:1510 lo_ioctl+0xca2/0x23b0 drivers/block/loop.c:1620 blkdev_ioctl+0x332/0x690 block/ioctl.c:585 block_ioctl+0xae/0xf0 fs/block_dev.c:1602 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466397 Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 48 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff301b1eef8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff301b1ef40 RCX: 0000000000466397 RDX: 00007ff301b1f050 RSI: 0000000000004c04 RDI: 000000000000000a RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ff301b1f050 R13: 00007ffd012499cf R14: 00007ff301b1f300 R15: 0000000000022000 BUG: sleeping function called from invalid context at mm/page_alloc.c:5167 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 10900, name: syz-executor.4 INFO: lockdep is turned off. irq event stamp: 8102 hardirqs last enabled at (8101): [] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 hardirqs last disabled at (8102): [] __alloc_pages_bulk+0x801/0x1090 mm/page_alloc.c:5279 softirqs last enabled at (7978): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (7978): [] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 softirqs last disabled at (6839): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (6839): [] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 CPU: 1 PID: 10900 Comm: syz-executor.4 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 ___might_sleep+0x4e5/0x6b0 kernel/sched/core.c:9154 prepare_alloc_pages+0x1c0/0x5a0 mm/page_alloc.c:5167 __alloc_pages+0x14d/0x5f0 mm/page_alloc.c:5363 stack_depot_save+0x361/0x490 lib/stackdepot.c:303 save_stack+0xf9/0x1f0 mm/page_owner.c:120 __set_page_owner+0x42/0x2f0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x9f2/0x1090 mm/page_alloc.c:5301 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x3ad/0x7f0 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x75/0x80 mm/vmalloc.c:3085 allocate_partitions block/partitions/core.c:106 [inline] check_partition block/partitions/core.c:128 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x4d9/0x1690 block/partitions/core.c:697 loop_reread_partitions drivers/block/loop.c:652 [inline] loop_set_status+0x6b1/0x8e0 drivers/block/loop.c:1510 lo_ioctl+0xca2/0x23b0 drivers/block/loop.c:1620 blkdev_ioctl+0x332/0x690 block/ioctl.c:585 block_ioctl+0xae/0xf0 fs/block_dev.c:1602 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466397 Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 48 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff301b1eef8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff301b1ef40 RCX: 0000000000466397 RDX: 00007ff301b1f050 RSI: 0000000000004c04 RDI: 000000000000000a RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ff301b1f050 R13: 00007ffd012499cf R14: 00007ff301b1f300 R15: 0000000000022000