====================================================== WARNING: possible circular locking dependency detected 4.14.0-next-20171124+ #51 Not tainted ------------------------------------------------------ syz-executor0/15388 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+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){.+.+}: spin_lock include/linux/spinlock.h:315 [inline] devtmpfsd+0x224/0x4b0 drivers/base/devtmpfs.c:392 -> #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-executor0/15388: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:75 stack backtrace: CPU: 0 PID: 15388 Comm: syz-executor0 Not tainted 4.14.0-next-20171124+ #51 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:00007f1bf358abe8 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: 00000000006f2608 R13: 00000000ffffffff R14: 00007f1bf358b6d4 R15: 0000000000000000 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=15397 comm=syz-executor3 encrypted_key: insufficient parameters specified print_req_error: 133 callbacks suppressed print_req_error: I/O error, dev loop0, sector 0 SELinux: unrecognized netlink message: protocol=4 nlmsg_type=27 sclass=netlink_tcpdiag_socket pig=15719 comm=syz-executor7 ip6tnl0: Invalid MTU 1879054852 requested, hw max 65392 Bearer <> rejected, illegal name SELinux: unrecognized netlink message: protocol=4 nlmsg_type=27 sclass=netlink_tcpdiag_socket pig=15719 comm=syz-executor7 Bearer <> rejected, illegal name loop_reread_partitions: partition scan of loop0 (-\t@r9hxGQ:[il L*@R-Tr-x) failed (rc=-13) print_req_error: I/O error, dev loop0, sector 0 print_req_error: I/O error, dev loop0, sector 0 buffer_io_error: 132 callbacks suppressed Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, async page read Buffer I/O error on dev loop0, logical block 0, async page read Buffer I/O error on dev loop0, logical block 0, async page read sctp: [Deprecated]: syz-executor1 (pid 15839) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead device gre0 entered promiscuous mode devpts: called with bogus options devpts: called with bogus options device gre0 entered promiscuous mode device gre0 entered promiscuous mode SELinux: unrecognized netlink message: protocol=4 nlmsg_type=257 sclass=netlink_tcpdiag_socket pig=16017 comm=syz-executor7 QAT: Invalid ioctl QAT: Invalid ioctl SELinux: unrecognized netlink message: protocol=4 nlmsg_type=257 sclass=netlink_tcpdiag_socket pig=15995 comm=syz-executor7 tmpfs: No value for mount option 'I' tmpfs: No value for mount option 'I' nla_parse: 24 callbacks suppressed netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor0'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=16213 comm=syz-executor0 could not allocate digest TFM handle t8g SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=16220 comm=syz-executor0 could not allocate digest TFM handle t8g QAT: Invalid ioctl sctp: [Deprecated]: syz-executor3 (pid 16277) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead netlink: 8 bytes leftover after parsing attributes in process `syz-executor5'. QAT: Invalid ioctl sctp: [Deprecated]: syz-executor3 (pid 16277) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. kauditd_printk_skb: 346 callbacks suppressed audit: type=1326 audit(1511674599.077:4757): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4758): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=49 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4759): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4760): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=305 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4761): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4762): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=68 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4763): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4764): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=16 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4765): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511674599.078:4766): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16493 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=165 compat=0 ip=0x452879 code=0x7ffc0000