====================================================== WARNING: possible circular locking dependency detected 4.14.0-next-20171124+ #51 Not tainted ------------------------------------------------------ syz-executor0/23243 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-executor0/23243: #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: 23243 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:00007fd437a53be8 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: 00007fd437a549c0 R15: 0000000000000000 device syz4 left promiscuous mode kvm [23262]: vcpu0, guest rIP: 0x9115 ignored wrmsr: 0x11e data 0x0 kvm [23262]: vcpu0, guest rIP: 0x9115 disabled perfctr wrmsr: 0xc2 data 0x0 kvm [23262]: vcpu0, guest rIP: 0x9115 disabled perfctr wrmsr: 0xc1 data 0x0 netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. kvm [23262]: vcpu0, guest rIP: 0x9115 ignored wrmsr: 0x11e data 0x0 kvm [23262]: vcpu0, guest rIP: 0x9115 disabled perfctr wrmsr: 0xc2 data 0x0 kvm [23262]: vcpu0, guest rIP: 0x9115 disabled perfctr wrmsr: 0xc1 data 0x0 sctp: [Deprecated]: syz-executor1 (pid 23361) Use of int in maxseg socket option. Use struct sctp_assoc_value instead netlink: 3 bytes leftover after parsing attributes in process `syz-executor4'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl kauditd_printk_skb: 49 callbacks suppressed audit: type=1326 audit(1511502030.276:5324): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23590 comm="syz-executor0" exe="/root/syz-executor0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0xffff0000 audit: type=1326 audit(1511502030.392:5325): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23590 comm="syz-executor0" exe="/root/syz-executor0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0xffff0000 audit: type=1326 audit(1511502031.149:5326): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 loop_reread_partitions: partition scan of loop0 (2°]€fI¸Òæ¶Ì”B±!S,›ùDÏ') failed (rc=-13) loop: Write error at byte offset 18446744073709547520, length 512. print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write loop_reread_partitions: partition scan of loop0 () failed (rc=-13) device gre0 entered promiscuous mode loop_reread_partitions: partition scan of loop0 (2°]€fI¸Òæ¶Ì”B±!S,›ùDÏ') failed (rc=-13) loop: Write error at byte offset 18446744073709547520, length 512. print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write loop_reread_partitions: partition scan of loop0 () failed (rc=-13) SELinux: failure in selinux_parse_skb(), unable to parse packet SELinux: failure in selinux_parse_skb(), unable to parse packet audit: type=1326 audit(1511502031.174:5327): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=55 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.174:5328): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.174:5329): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.174:5330): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=92 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.174:5331): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.174:5332): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511502031.176:5333): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=23832 comm="syz-executor5" exe="/root/syz-executor5" sig=0 arch=c000003e syscall=14 compat=0 ip=0x452879 code=0x7ffc0000 nla_parse: 17 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor3'. selinux_nlmsg_perm: 4 callbacks suppressed SELinux: unrecognized netlink message: protocol=9 nlmsg_type=30 sclass=netlink_audit_socket pig=24199 comm=syz-executor2 netlink: 3 bytes leftover after parsing attributes in process `syz-executor3'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 24262 Comm: syz-executor7 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 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:425 [inline] slab_alloc_node mm/slab.c:3293 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3636 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:983 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1144 [inline] netlink_sendmsg+0xa86/0xe70 net/netlink/af_netlink.c:1836 sock_sendmsg_nosec net/socket.c:632 [inline] sock_sendmsg+0xca/0x110 net/socket.c:642 ___sys_sendmsg+0x75b/0x8a0 net/socket.c:2048 __sys_sendmsg+0xe5/0x210 net/socket.c:2082 SYSC_sendmsg net/socket.c:2093 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2089 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f7347f25be8 EFLAGS: 00000212 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000004800 RSI: 0000000020332fc8 RDI: 0000000000000013 RBP: 00007f7347f25a20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b757e R13: 00007f7347f25b58 R14: 00000000004b758e R15: 0000000000000000