======================================================
WARNING: possible circular locking dependency detected
4.15.0-rc1+ #200 Not tainted
------------------------------------------------------
syz-executor2/17245 is trying to acquire lock:
 (console_lock){+.+.}, at: [<0000000073d33730>] vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:219

but task is already holding lock:
 (&pipe->mutex/1){+.+.}, at: [<000000003cf3da03>] pipe_lock_nested fs/pipe.c:67 [inline]
 (&pipe->mutex/1){+.+.}, at: [<000000003cf3da03>] pipe_lock+0x56/0x70 fs/pipe.c:75

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&pipe->mutex/1){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
       pipe_lock_nested fs/pipe.c:67 [inline]
       pipe_lock+0x56/0x70 fs/pipe.c:75
       iter_file_splice_write+0x264/0xf30 fs/splice.c:699
       do_splice_from fs/splice.c:851 [inline]
       do_splice fs/splice.c:1147 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x7d5/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #2 (sb_writers){.+.+}:
       rq_lock kernel/sched/sched.h:1766 [inline]
       scheduler_tick+0xe1/0x410 kernel/sched/core.c:3021

-> #1 ((completion)&req.done){+.+.}:
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       complete_acquire include/linux/completion.h:40 [inline]
       __wait_for_common kernel/sched/completion.c:109 [inline]
       wait_for_common kernel/sched/completion.c:123 [inline]
       wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144
       devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115
       device_add+0x120f/0x1640 drivers/base/core.c:1824
       device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430
       device_create_vargs drivers/base/core.c:2470 [inline]
       device_create+0xda/0x110 drivers/base/core.c:2506
       vcs_make_sysfs+0x35/0x60 drivers/tty/vt/vc_screen.c:629
       vc_allocate+0x4b7/0x6b0 drivers/tty/vt/vt.c:797
       con_install+0x52/0x440 drivers/tty/vt/vt.c:2876
       tty_driver_install_tty drivers/tty/tty_io.c:1215 [inline]
       tty_init_dev+0xf6/0x4a0 drivers/tty/tty_io.c:1315
       tty_open_by_driver drivers/tty/tty_io.c:1942 [inline]
       tty_open+0x608/0xab0 drivers/tty/tty_io.c:1990
       chrdev_open+0x257/0x730 fs/char_dev.c:417
       do_dentry_open+0x682/0xd70 fs/open.c:752
       vfs_open+0x107/0x230 fs/open.c:866
       do_last fs/namei.c:3388 [inline]
       path_openat+0x1157/0x3530 fs/namei.c:3528
       do_filp_open+0x25b/0x3b0 fs/namei.c:3563
       do_sys_open+0x502/0x6d0 fs/open.c:1059
       SYSC_open fs/open.c:1077 [inline]
       SyS_open+0x2d/0x40 fs/open.c:1072
       entry_SYSCALL_64_fastpath+0x1f/0x96

-> #0 (console_lock){+.+.}:
       check_prevs_add kernel/locking/lockdep.c:2031 [inline]
       validate_chain kernel/locking/lockdep.c:2473 [inline]
       __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
       lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
       console_lock+0x4b/0x80 kernel/printk/printk.c:2047
       vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:219
       do_loop_readv_writev fs/read_write.c:673 [inline]
       do_iter_read+0x3db/0x5b0 fs/read_write.c:897
       vfs_readv+0x121/0x1c0 fs/read_write.c:959
       kernel_readv fs/splice.c:361 [inline]
       default_file_splice_read+0x508/0xae0 fs/splice.c:416
       do_splice_to+0x110/0x170 fs/splice.c:880
       do_splice fs/splice.c:1173 [inline]
       SYSC_splice fs/splice.c:1402 [inline]
       SyS_splice+0x11a8/0x1630 fs/splice.c:1382
       entry_SYSCALL_64_fastpath+0x1f/0x96

other info that might help us debug this:

Chain exists of:
  console_lock --> sb_writers --> &pipe->mutex/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pipe->mutex/1);
                               lock(sb_writers);
                               lock(&pipe->mutex/1);
  lock(console_lock);

 *** DEADLOCK ***

1 lock held by syz-executor2/17245:
 #0:  (&pipe->mutex/1){+.+.}, at: [<000000003cf3da03>] pipe_lock_nested fs/pipe.c:67 [inline]
 #0:  (&pipe->mutex/1){+.+.}, at: [<000000003cf3da03>] pipe_lock+0x56/0x70 fs/pipe.c:75

stack backtrace:
CPU: 1 PID: 17245 Comm: syz-executor2 Not tainted 4.15.0-rc1+ #200
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_circular_bug+0x42d/0x610 kernel/locking/lockdep.c:1271
 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914
 check_prevs_add kernel/locking/lockdep.c:2031 [inline]
 validate_chain kernel/locking/lockdep.c:2473 [inline]
 __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
 console_lock+0x4b/0x80 kernel/printk/printk.c:2047
 vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:219
 do_loop_readv_writev fs/read_write.c:673 [inline]
 do_iter_read+0x3db/0x5b0 fs/read_write.c:897
 vfs_readv+0x121/0x1c0 fs/read_write.c:959
 kernel_readv fs/splice.c:361 [inline]
 default_file_splice_read+0x508/0xae0 fs/splice.c:416
 do_splice_to+0x110/0x170 fs/splice.c:880
 do_splice fs/splice.c:1173 [inline]
 SYSC_splice fs/splice.c:1402 [inline]
 SyS_splice+0x11a8/0x1630 fs/splice.c:1382
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007f3baacbbc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9
RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000015
RBP: 000000000000015d R08: 0000000000008000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ef158
R13: 00000000ffffffff R14: 00007f3baacbc6d4 R15: 0000000000000000
QAT: Invalid ioctl
QAT: Invalid ioctl
nla_parse: 21 callbacks suppressed
netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'.
binder_alloc: binder_alloc_mmap_handler: 17403 20000000-20002000 already mapped failed -16
netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'.
netlink: 2 bytes leftover after parsing attributes in process `syz-executor7'.
device lo entered promiscuous mode
device teql0 entered promiscuous mode
netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'.
netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'.
device teql0 left promiscuous mode
netlink: 17 bytes leftover after parsing attributes in process `syz-executor1'.
QAT: Invalid ioctl
QAT: Invalid ioctl
netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'.
netlink: 17 bytes leftover after parsing attributes in process `syz-executor1'.
netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'.
PF_BRIDGE: br_mdb_parse() with non-bridge
PF_BRIDGE: br_mdb_parse() with non-bridge
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 18481 Comm: syz-executor3 Not tainted 4.15.0-rc1+ #200
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3371 [inline]
 kmem_cache_alloc+0x47/0x760 mm/slab.c:3545
 sock_alloc_inode+0x70/0x300 net/socket.c:250
 alloc_inode+0x65/0x180 fs/inode.c:208
 new_inode_pseudo+0x69/0x190 fs/inode.c:890
 sock_alloc+0x41/0x270 net/socket.c:565
 __sock_create+0x148/0x850 net/socket.c:1225
 sock_create net/socket.c:1301 [inline]
 SYSC_socketpair net/socket.c:1373 [inline]
 SyS_socketpair+0x115/0x640 net/socket.c:1352
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007f95714c2c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f95714c2aa0 RCX: 00000000004529d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f95714c2a90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020697ff8 R11: 0000000000000212 R12: 00000000004b759b
R13: 00007f95714c2bc8 R14: 00000000004b759b R15: 0000000000000000
socket: no more sockets
dccp_invalid_packet: P.Data Offset(4) too small
dccp_invalid_packet: P.Data Offset(4) too small
syz-executor6 (18737): attempted to duplicate a private mapping with mremap.  This is not supported.
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 18879 Comm: syz-executor4 Not tainted 4.15.0-rc1+ #200
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc mm/slab.c:3371 [inline]
 __do_kmalloc mm/slab.c:3709 [inline]
 __kmalloc_track_caller+0x5f/0x760 mm/slab.c:3726
 memdup_user+0x2c/0x90 mm/util.c:164
 kvm_arch_vcpu_ioctl+0x1ba3/0x4710 arch/x86/kvm/x86.c:3485
 kvm_vcpu_ioctl+0x240/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2703
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007fe80337bc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe80337baa0 RCX: 00000000004529d9
RDX: 00000000201e4c00 RSI: 000000004400ae8f RDI: 0000000000000016
RBP: 00007fe80337ba90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b759b
R13: 00007fe80337bbc8 R14: 00000000004b759b R15: 0000000000000000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 18914 Comm: syz-executor4 Not tainted 4.15.0-rc1+ #200
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 fail_dump lib/fault-inject.c:51 [inline]
 should_fail+0x8c0/0xa40 lib/fault-inject.c:149
 should_failslab+0xec/0x120 mm/failslab.c:32
 slab_pre_alloc_hook mm/slab.h:421 [inline]
 slab_alloc_node mm/slab.c:3292 [inline]
 kmem_cache_alloc_node_trace+0x5a/0x760 mm/slab.c:3654
 __do_kmalloc_node mm/slab.c:3674 [inline]
 __kmalloc_node+0x33/0x70 mm/slab.c:3682
 kmalloc_node include/linux/slab.h:541 [inline]
 kvmalloc_node+0x99/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:540 [inline]
 kvzalloc include/linux/mm.h:548 [inline]
 recalculate_apic_map+0x2e8/0xf50 arch/x86/kvm/lapic.c:178
 apic_set_spiv arch/x86/kvm/lapic.c:251 [inline]
 kvm_apic_set_state+0x88d/0xb80 arch/x86/kvm/lapic.c:2277
 kvm_vcpu_ioctl_set_lapic arch/x86/kvm/x86.c:2943 [inline]
 kvm_arch_vcpu_ioctl+0x1bc2/0x4710 arch/x86/kvm/x86.c:3489
 kvm_vcpu_ioctl+0x240/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2703
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x4529d9
RSP: 002b:00007fe80337bc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe80337baa0 RCX: 00000000004529d9
RDX: 00000000201e4c00 RSI: 000000004400ae8f RDI: 0000000000000016
RBP: 00007fe80337ba90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b759b
R13: 00007fe80337bbc8 R14: 00000000004b759b R15: 0000000000000000