======================================================
WARNING: possible circular locking dependency detected
5.14.0-rc1-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/15099 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:
ffff8880b9c4d0c8 (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:

-> #1 (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
       rmqueue_pcplist+0x10c/0x4d0 mm/page_alloc.c:3663
       rmqueue+0x1eb4/0x22e0 mm/page_alloc.c:3701
       get_page_from_freelist+0x4b3/0xa30 mm/page_alloc.c:4163
       __alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5374
       stack_depot_save+0x361/0x490 lib/stackdepot.c:303
       kasan_save_stack+0x3e/0x50 mm/kasan/common.c:40
       kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:348
       __call_rcu kernel/rcu/tree.c:3029 [inline]
       call_rcu+0x1a0/0xa20 kernel/rcu/tree.c:3109
       context_switch kernel/sched/core.c:4686 [inline]
       __schedule+0xc0f/0x11f0 kernel/sched/core.c:5940
       preempt_schedule_notrace+0x12c/0x170 kernel/sched/core.c:6179
       preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36
       rcu_read_unlock_sched_notrace include/linux/rcupdate.h:809 [inline]
       trace_lock_release+0xa1/0x150 include/trace/events/lock.h:58
       lock_release+0x81/0x7b0 kernel/locking/lockdep.c:5636
       might_alloc include/linux/sched/mm.h:199 [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+0x41/0x340 mm/slub.c:2994
       getname_flags+0xba/0x640 fs/namei.c:138
       user_path_at_empty+0x28/0x50 fs/namei.c:2747
       user_path_at include/linux/namei.h:57 [inline]
       vfs_statx+0x102/0x3d0 fs/stat.c:203
       vfs_fstatat fs/stat.c:225 [inline]
       vfs_lstat include/linux/fs.h:3386 [inline]
       __do_sys_newlstat fs/stat.c:380 [inline]
       __se_sys_newlstat+0xab/0x770 fs/stat.c:374
       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

-> #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_user+0x70/0x80 mm/vmalloc.c:3101
       vb2_vmalloc_alloc+0xbc/0x270 drivers/media/common/videobuf2/videobuf2-vmalloc.c:48
       __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:233 [inline]
       __vb2_queue_alloc+0x7c8/0x1550 drivers/media/common/videobuf2/videobuf2-core.c:438
       vb2_core_reqbufs+0x9cd/0x1000 drivers/media/common/videobuf2/videobuf2-core.c:811
       v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:578 [inline]
       v4l2_m2m_ioctl_reqbufs+0xe9/0x1c0 drivers/media/v4l2-core/v4l2-mem2mem.c:1316
       __video_do_ioctl+0x9c3/0xd90 drivers/media/v4l2-core/v4l2-ioctl.c:2951
       video_usercopy+0xa2a/0x1080 drivers/media/v4l2-core/v4l2-ioctl.c:3299
       v4l2_ioctl+0x181/0x1d0 drivers/media/v4l2-core/v4l2-dev.c:364
       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:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#2);
                               lock(fs_reclaim);
                               lock(lock#2);
  lock(fs_reclaim);

 *** DEADLOCK ***

2 locks held by syz-executor.0/15099:
 #0: ffff88802c7272f0 (&ctx->vb_mutex){+.+.}-{3:3}, at: __video_do_ioctl+0x51b/0xd90 drivers/media/v4l2-core/v4l2-ioctl.c:2919
 #1: ffff8880b9c4d0c8 (lock#2){..-.}-{2:2}, at: local_lock_acquire+0x7/0x130 include/linux/local_lock_internal.h:41

stack backtrace:
CPU: 0 PID: 15099 Comm: syz-executor.0 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_user+0x70/0x80 mm/vmalloc.c:3101
 vb2_vmalloc_alloc+0xbc/0x270 drivers/media/common/videobuf2/videobuf2-vmalloc.c:48
 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:233 [inline]
 __vb2_queue_alloc+0x7c8/0x1550 drivers/media/common/videobuf2/videobuf2-core.c:438
 vb2_core_reqbufs+0x9cd/0x1000 drivers/media/common/videobuf2/videobuf2-core.c:811
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:578 [inline]
 v4l2_m2m_ioctl_reqbufs+0xe9/0x1c0 drivers/media/v4l2-core/v4l2-mem2mem.c:1316
 __video_do_ioctl+0x9c3/0xd90 drivers/media/v4l2-core/v4l2-ioctl.c:2951
 video_usercopy+0xa2a/0x1080 drivers/media/v4l2-core/v4l2-ioctl.c:3299
 v4l2_ioctl+0x181/0x1d0 drivers/media/v4l2-core/v4l2-dev.c:364
 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: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fdf3381b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000020001480 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc1d9d057f R14: 00007fdf3381b300 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: 15099, name: syz-executor.0
INFO: lockdep is turned off.
irq event stamp: 202
hardirqs last  enabled at (201): [<ffffffff89db217b>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
hardirqs last  enabled at (201): [<ffffffff89db217b>] _raw_spin_unlock_irqrestore+0x8b/0x120 kernel/locking/spinlock.c:191
hardirqs last disabled at (202): [<ffffffff81be9e01>] __alloc_pages_bulk+0x801/0x1090 mm/page_alloc.c:5279
softirqs last  enabled at (0): [<ffffffff814b18eb>] copy_process+0x147b/0x5b00 kernel/fork.c:2065
softirqs last disabled at (0): [<0000000000000000>] 0x0
CPU: 0 PID: 15099 Comm: syz-executor.0 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_user+0x70/0x80 mm/vmalloc.c:3101
 vb2_vmalloc_alloc+0xbc/0x270 drivers/media/common/videobuf2/videobuf2-vmalloc.c:48
 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:233 [inline]
 __vb2_queue_alloc+0x7c8/0x1550 drivers/media/common/videobuf2/videobuf2-core.c:438
 vb2_core_reqbufs+0x9cd/0x1000 drivers/media/common/videobuf2/videobuf2-core.c:811
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:578 [inline]
 v4l2_m2m_ioctl_reqbufs+0xe9/0x1c0 drivers/media/v4l2-core/v4l2-mem2mem.c:1316
 __video_do_ioctl+0x9c3/0xd90 drivers/media/v4l2-core/v4l2-ioctl.c:2951
 video_usercopy+0xa2a/0x1080 drivers/media/v4l2-core/v4l2-ioctl.c:3299
 v4l2_ioctl+0x181/0x1d0 drivers/media/v4l2-core/v4l2-dev.c:364
 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: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fdf3381b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000020001480 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc1d9d057f R14: 00007fdf3381b300 R15: 0000000000022000