audit: type=1326 audit(1511020088.252:3574): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=31477 comm="syz-executor3" exe="/root/syz-executor3" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 ====================================================== WARNING: possible circular locking dependency detected 4.14.0+ #183 Not tainted ------------------------------------------------------ syz-executor2/31489 is trying to acquire lock: (console_lock){+.+.}, at: [] vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:219 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] cache_grow_end.part.37+0x3a/0x180 mm/slab.c:2726 -> #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-executor2/31489: #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: 31489 Comm: syz-executor2 Not tainted 4.14.0+ #183 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: 0033:0x452879 RSP: 002b:00007f4130784be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000017 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000086 R08: 0000000000000003 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2620 R13: 00000000ffffffff R14: 00007f41307856d4 R15: 0000000000000000 QAT: Invalid ioctl QAT: Invalid ioctl nla_parse: 6 callbacks suppressed netlink: 14 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor1'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl device lo entered promiscuous mode IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready device gre0 entered promiscuous mode netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 6 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 6 bytes leftover after parsing attributes in process `syz-executor5'. sock: process `syz-executor3' is using obsolete setsockopt SO_BSDCOMPAT netlink: 14 bytes leftover after parsing attributes in process `syz-executor1'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl netlink: 16 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 16 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 72 bytes leftover after parsing attributes in process `syz-executor3'. selinux_nlmsg_perm: 2 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=32400 comm=syz-executor7 device gre0 entered promiscuous mode kauditd_printk_skb: 493 callbacks suppressed audit: type=1326 audit(1511020094.246:4067): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=32728 comm="syz-executor4" exe="/root/syz-executor4" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0xffff0000 sg_write: data in/out 822404280/197 bytes for SCSI command 0x12-- guessing data in; program syz-executor0 not setting count and/or reply_len properly sg_write: data in/out 262364/161 bytes for SCSI command 0xff-- guessing data in; program syz-executor0 not setting count and/or reply_len properly sg_write: data in/out 822404280/197 bytes for SCSI command 0x12-- guessing data in; program syz-executor0 not setting count and/or reply_len properly audit: type=1326 audit(1511020094.408:4068): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=32728 comm="syz-executor4" exe="/root/syz-executor4" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0xffff0000 sg_write: data in/out 262364/161 bytes for SCSI command 0xff-- guessing data in; program syz-executor0 not setting count and/or reply_len properly device gre0 entered promiscuous mode tmpfs: No value for mount option 'ñ' tmpfs: No value for mount option 'ñ' print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write nla_parse: 21 callbacks suppressed netlink: 9 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 9 bytes leftover after parsing attributes in process `syz-executor1'. audit: type=1326 audit(1511020094.997:4069): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=383 comm="syz-executor3" exe="/root/syz-executor3" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x0 audit: type=1326 audit(1511020094.997:4070): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=383 comm="syz-executor3" exe="/root/syz-executor3" sig=31 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x0 audit: type=1326 audit(1511020095.029:4071): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=383 comm="syz-executor3" exe="/root/syz-executor3" sig=31 arch=c000003e syscall=35 compat=0 ip=0x47dee1 code=0x0 QAT: Invalid ioctl QAT: Device 0 not found print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write 9pnet_virtio: no channels available for device ./file0 netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. QAT: Invalid ioctl QAT: Device 0 not found netlink: 1 bytes leftover after parsing attributes in process `syz-executor3'. audit: type=1326 audit(1511020095.242:4072): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=431 comm="syz-executor2" exe="/root/syz-executor2" sig=9 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x0 print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write audit: type=1326 audit(1511020095.370:4073): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=431 comm="syz-executor2" exe="/root/syz-executor2" sig=9 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x0 print_req_error: I/O error, dev loop0, sector 0 devpts: called with bogus options Buffer I/O error on dev loop0, logical block 0, lost async page write devpts: called with bogus options device gre0 entered promiscuous mode print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write netlink: 14 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 14 bytes leftover after parsing attributes in process `syz-executor2'. print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write QAT: Invalid ioctl QAT: Invalid ioctl print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write audit: type=1326 audit(1511020096.670:4074): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=713 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'. audit: type=1326 audit(1511020096.692:4075): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=713 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=9 compat=0 ip=0x452879 code=0x7ffc0000 device gre0 left promiscuous mode audit: type=1326 audit(1511020096.693:4076): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=713 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'. print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl print_req_error: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0, logical block 0, lost async page write QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl skbuff: bad partial csum: csum=53081/14726 len=2273 QAT: Invalid ioctl skbuff: bad partial csum: csum=53081/14726 len=2273 sg_write: data in/out 524252/4 bytes for SCSI command 0x19-- guessing data in; program syz-executor4 not setting count and/or reply_len properly SELinux: unrecognized netlink message: protocol=4 nlmsg_type=3 sclass=netlink_tcpdiag_socket pig=1124 comm=syz-executor1 QAT: Invalid ioctl QAT: Invalid ioctl sg_write: data in/out 524252/4 bytes for SCSI command 0x19-- guessing data in; program syz-executor4 not setting count and/or reply_len properly QAT: Invalid ioctl