====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz-execprog/8460 is trying to acquire lock: ffffffff8ba9c460 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_acquire+0xf7/0x160 mm/page_alloc.c:4574 but task is already holding lock: ffff8880b9d4d660 (lock#2){-.-.}-{2:2}, at: __alloc_pages_bulk+0x4ad/0x1870 mm/page_alloc.c:5279 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (lock#2){-.-.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:42 [inline] free_unref_page+0x1bf/0x690 mm/page_alloc.c:3427 mm_free_pgd kernel/fork.c:636 [inline] __mmdrop+0xcb/0x3f0 kernel/fork.c:687 mmdrop include/linux/sched/mm.h:49 [inline] finish_task_switch.isra.0+0x6da/0xa50 kernel/sched/core.c:4582 context_switch kernel/sched/core.c:4686 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5940 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6328 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_release+0x3f1/0x720 kernel/locking/lockdep.c:5633 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+0x3e/0x3a0 mm/slub.c:2994 prepare_creds+0x3f/0x7b0 kernel/cred.c:262 access_override_creds fs/open.c:355 [inline] do_faccessat+0x3f4/0x850 fs/open.c:419 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __fs_reclaim_acquire mm/page_alloc.c:4552 [inline] fs_reclaim_acquire+0x117/0x160 mm/page_alloc.c:4566 prepare_alloc_pages+0x15c/0x580 mm/page_alloc.c:5164 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5363 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x8b9/0x1870 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+0x39d/0x960 mm/vmalloc.c:2966 vmalloc_user+0x67/0x80 mm/vmalloc.c:3101 kcov_mmap+0x2b/0x140 kernel/kcov.c:465 call_mmap include/linux/fs.h:2119 [inline] mmap_region+0xcde/0x1760 mm/mmap.c:1808 do_mmap+0x86e/0x1180 mm/mmap.c:1584 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x4a8/0x620 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#2); lock(fs_reclaim); lock(lock#2); lock(fs_reclaim); *** DEADLOCK *** 2 locks held by syz-execprog/8460: #0: ffff88802c71ab28 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88802c71ab28 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x15c/0x290 mm/util.c:517 #1: ffff8880b9d4d660 (lock#2){-.-.}-{2:2}, at: __alloc_pages_bulk+0x4ad/0x1870 mm/page_alloc.c:5279 stack backtrace: CPU: 1 PID: 8460 Comm: syz-execprog 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+0xcd/0x134 lib/dump_stack.c:105 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __fs_reclaim_acquire mm/page_alloc.c:4552 [inline] fs_reclaim_acquire+0x117/0x160 mm/page_alloc.c:4566 prepare_alloc_pages+0x15c/0x580 mm/page_alloc.c:5164 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5363 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x8b9/0x1870 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+0x39d/0x960 mm/vmalloc.c:2966 vmalloc_user+0x67/0x80 mm/vmalloc.c:3101 kcov_mmap+0x2b/0x140 kernel/kcov.c:465 call_mmap include/linux/fs.h:2119 [inline] mmap_region+0xcde/0x1760 mm/mmap.c:1808 do_mmap+0x86e/0x1180 mm/mmap.c:1584 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x4a8/0x620 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4b132a Code: e8 db 57 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 4c 8b 54 24 28 4c 8b 44 24 30 4c 8b 4c 24 38 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 40 ff ff ff ff 48 c7 44 24 48 RSP: 002b:000000c0004efa10 EFLAGS: 00000202 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000c000020800 RCX: 00000000004b132a RDX: 0000000000000003 RSI: 0000000000080000 RDI: 0000000000000000 RBP: 000000c0004efa70 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000727f1a R13: 000000000000010a R14: 0000000000000200 R15: 0000000000000100 BUG: sleeping function called from invalid context at mm/page_alloc.c:5167 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 8460, name: syz-execprog INFO: lockdep is turned off. irq event stamp: 21990 hardirqs last enabled at (21989): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (21989): [] _raw_spin_unlock_irqrestore+0x50/0x70 kernel/locking/spinlock.c:191 hardirqs last disabled at (21990): [] __alloc_pages_bulk+0x1017/0x1870 mm/page_alloc.c:5279 softirqs last enabled at (21198): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (21198): [] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 softirqs last disabled at (21129): [] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (21129): [] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 CPU: 1 PID: 8460 Comm: syz-execprog 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+0xcd/0x134 lib/dump_stack.c:105 ___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:9154 prepare_alloc_pages+0x3da/0x580 mm/page_alloc.c:5167 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5363 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2433 [inline] __alloc_pages_bulk+0x8b9/0x1870 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+0x39d/0x960 mm/vmalloc.c:2966 vmalloc_user+0x67/0x80 mm/vmalloc.c:3101 kcov_mmap+0x2b/0x140 kernel/kcov.c:465 call_mmap include/linux/fs.h:2119 [inline] mmap_region+0xcde/0x1760 mm/mmap.c:1808 do_mmap+0x86e/0x1180 mm/mmap.c:1584 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x4a8/0x620 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4b132a Code: e8 db 57 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 4c 8b 54 24 28 4c 8b 44 24 30 4c 8b 4c 24 38 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 40 ff ff ff ff 48 c7 44 24 48 RSP: 002b:000000c0004efa10 EFLAGS: 00000202 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000c000020800 RCX: 00000000004b132a RDX: 0000000000000003 RSI: 0000000000080000 RDI: 0000000000000000 RBP: 000000c0004efa70 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000727f1a R13: 000000000000010a R14: 0000000000000200 R15: 0000000000000100