====================================================== WARNING: possible circular locking dependency detected 4.14.0-next-20171117+ #45 Not tainted ------------------------------------------------------ syz-executor1/8758 is trying to acquire lock: (console_lock){+.+.}, at: [] vcs_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_lock fs/pipe.c:75 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_wait+0x1e6/0x280 fs/pipe.c:123 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){.+.+}: try_to_wake_up+0xbc/0x1600 kernel/sched/core.c:1988 -> #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_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 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 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-executor1/8758: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock fs/pipe.c:75 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_wait+0x1e6/0x280 fs/pipe.c:123 stack backtrace: CPU: 1 PID: 8758 Comm: syz-executor1 Not tainted 4.14.0-next-20171117+ #45 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_write+0x14d/0xca0 drivers/tty/vt/vc_screen.c:397 __vfs_write+0xef/0x970 fs/read_write.c:480 __kernel_write+0xfe/0x350 fs/read_write.c:501 write_pipe_buf+0x175/0x220 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x328/0x730 fs/splice.c:626 splice_from_pipe+0x1e9/0x330 fs/splice.c:661 default_file_splice_write+0x40/0x90 fs/splice.c:809 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 RIP: 0033:0x452879 RSP: 002b:00007f1226ffcbe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 0000000000000086 R08: 00000000fffff5fc R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000 R13: 0000000000a6f7ff R14: 00007f1226ffd9c0 R15: 0000000000000000 tmpfs: Bad mount option —peUÑ”%0ØÚì1D…# 0t‰Pe€üº« ?˜9â(B¤òÚg8)²º¸ÌW, network identity 4711 QAT: Invalid ioctl CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000f80 RIP = 0x0000000000000000 RFLAGS=0x00000002 DR7 = 0x0000000000000400 QAT: Invalid ioctl Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0x0010, attr=0x0009b, limit=0x000fffff, base=0x0000000000000000 DS: sel=0x0018, attr=0x00093, limit=0x000fffff, base=0x0000000000000000 SS: sel=0x0018, attr=0x00093, limit=0x000fffff, base=0x0000000000000000 ES: sel=0x0018, attr=0x00093, limit=0x000fffff, base=0x0000000000000000 FS: sel=0x0018, attr=0x00093, limit=0x000fffff, base=0x0000000000000000 GS: sel=0x0018, attr=0x00093, limit=0x000fffff, base=0x0000000000000000 GDTR: limit=0x000007ff, base=0x0000000000001000 LDTR: sel=0x0008, attr=0x04082, limit=0x000007ff, base=0x0000000000001800 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x000000000000c000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811bcac3 RSP = 0xffff8801d0a274c8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007f205e584700 GSBase=ffff8801db400000 TRBase=ffff8801db423140 GDTBase=ffffffffff577000 IDTBase=ffffffffff57b000 CR0=0000000080050033 CR3=00000001cefd0000 CR4=00000000001426f0 Sysenter RSP=0000000000000000 CS:RIP=0010:ffffffff85107730 EFER = 0x0000000000000d01 PAT = 0x0000000000000000 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=0000004a EntryControls=0000d1ff ExitControls=0023efff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=00000000 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000000 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffc2d1659fff EPT pointer = 0x00000001c0cc701e device lo entered promiscuous mode SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=9205 comm=syz-executor7 device gre0 entered promiscuous mode nla_parse: 6 callbacks suppressed netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. device gre0 left promiscuous mode device gre0 entered promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. device gre0 left promiscuous mode device gre0 entered promiscuous mode netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor7'. QAT: Invalid ioctl device syz7 entered promiscuous mode netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'. sctp: [Deprecated]: syz-executor5 (pid 9579) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor5 (pid 9627) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead device gre0 entered promiscuous mode sctp: [Deprecated]: syz-executor6 (pid 9792) Use of int in maxseg socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor6 (pid 9820) Use of int in maxseg socket option. Use struct sctp_assoc_value instead QAT: Invalid ioctl QAT: Invalid ioctl device gre0 entered promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. device eql entered promiscuous mode QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl pit: kvm: requested 5866 ns i8254 timer period limited to 500000 ns device gre0 entered promiscuous mode *** Guest State *** CR0: actual=0x0000000080000031, shadow=0x0000000060000011, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000010, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000000 RIP = 0x000000000000fff0 RFLAGS=0x00010000 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000f80 CS:RIP=0030:0000000000002810 CS: sel=0x0030, attr=0x0409b, limit=0x000fffff, base=0x0000000000000000 DS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 SS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 ES: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 FS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GS: sel=0x0038, attr=0x04093, limit=0x000fffff, base=0x0000000000000000 GDTR: limit=0x000007ff, base=0x0000000000001000 LDTR: sel=0x0008, attr=0x04082, limit=0x000007ff, base=0x0000000000001800 IDTR: limit=0x000001ff, base=0x0000000000003800 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000001 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811bcac3 RSP = 0xffff8801ccf674c8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007f8e5039a700 GSBase=ffff8801db400000 TRBase=ffff8801db423140 GDTBase=ffffffffff577000 IDTBase=ffffffffff57b000 CR0=0000000080050033 CR3=00000001c4335000 CR4=00000000001426f0 Sysenter RSP=0000000000000000 CS:RIP=0010:ffffffff85107730 EFER = 0x0000000000000d01 PAT = 0x0000000000000000 *** Control State *** PinBased=0000003f CPUBased=b699edfa SecondaryExec=0000004a EntryControls=0000d1ff ExitControls=0023efff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=80000306 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000001 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffbf42f1ba92 EPT pointer = 0x00000001c738801e kvm [10757]: vcpu0, guest rIP: 0x9115 Hyper-V uhandled wrmsr: 0x4000008f data 0x0 kvm [10757]: vcpu0, guest rIP: 0x9115 Hyper-V uhandled wrmsr: 0x4000008e data 0x0 kvm [10757]: vcpu0, guest rIP: 0x9115 Hyper-V uhandled wrmsr: 0x4000008d data 0x0 kauditd_printk_skb: 198 callbacks suppressed audit: type=1326 audit(1511079943.084:806): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 nla_parse: 19 callbacks suppressed netlink: 5 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'. audit: type=1326 audit(1511079943.084:807): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=319 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:808): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:809): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=16 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:810): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:811): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=29 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:812): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:813): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=287 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:814): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511079943.084:815): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=10890 comm="syz-executor0" exe="/root/syz-executor0" sig=0 arch=c000003e syscall=278 compat=0 ip=0x452879 code=0x7ffc0000