====================================================== WARNING: possible circular locking dependency detected 4.14.0+ #183 Not tainted ------------------------------------------------------ syz-executor7/9329 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] lockref_get_not_dead+0x19/0x80 lib/lockref.c:180 -> #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-executor7/9329: #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: 9329 Comm: syz-executor7 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:00007f9a27e76be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 0000000000000015 RSI: 0000000000000000 RDI: 0000000000000013 RBP: 0000000000000086 R08: 0000000000000003 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4d68 R13: 00000000ffffffff R14: 00007f9a27e776d4 R15: 0000000000000000 device gre0 entered promiscuous mode device lo entered promiscuous mode netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. QAT: Invalid ioctl QAT: Invalid ioctl netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor2'. device gre0 entered promiscuous mode device gre0 entered promiscuous mode sg_write: data in/out 262108/36 bytes for SCSI command 0x42-- guessing data in; program syz-executor7 not setting count and/or reply_len properly sg_write: data in/out 262108/36 bytes for SCSI command 0x42-- guessing data in; program syz-executor7 not setting count and/or reply_len properly audit: type=1326 audit(1511006324.410:903): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.411:904): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=9 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.415:905): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.417:906): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=298 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.417:907): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.422:908): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=9 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.423:909): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006324.424:910): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9568 comm="syz-executor2" exe="/root/syz-executor2" sig=0 arch=c000003e syscall=298 compat=0 ip=0x452879 code=0x7ffc0000 device gre0 entered promiscuous mode Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable QAT: Invalid ioctl rfkill: input handler disabled rfkill: input handler enabled nla_parse: 9 callbacks suppressed netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor1'. kauditd_printk_skb: 124 callbacks suppressed audit: type=1326 audit(1511006326.374:1035): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. audit: type=1326 audit(1511006326.401:1036): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=9 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.401:1037): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.401:1038): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.401:1039): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=41 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.402:1040): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.404:1041): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.405:1042): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=49 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.405:1043): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 audit: type=1326 audit(1511006326.405:1044): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=9944 comm="syz-executor6" exe="/root/syz-executor6" sig=0 arch=c000003e syscall=202 compat=0 ip=0x452879 code=0x7ffc0000 device gre0 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'. netlink: 11 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 11 bytes leftover after parsing attributes in process `syz-executor1'. device lo left promiscuous mode sock: process `syz-executor1' is using obsolete setsockopt SO_BSDCOMPAT FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 10353 Comm: syz-executor5 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 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 __build_skb+0x9d/0x450 net/core/skbuff.c:281 __napi_alloc_skb+0x173/0x2c0 net/core/skbuff.c:482 napi_alloc_skb include/linux/skbuff.h:2637 [inline] napi_get_frags+0x61/0x130 net/core/dev.c:5020 tun_napi_alloc_frags drivers/net/tun.c:1294 [inline] tun_get_user+0x1bb7/0x36d0 drivers/net/tun.c:1634 tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1797 call_write_iter include/linux/fs.h:1772 [inline] do_iter_readv_writev+0x531/0x7f0 fs/read_write.c:653 do_iter_write+0x15a/0x540 fs/read_write.c:932 vfs_writev+0x18a/0x340 fs/read_write.c:977 do_writev+0xfc/0x2a0 fs/read_write.c:1012 SYSC_writev fs/read_write.c:1085 [inline] SyS_writev+0x27/0x30 fs/read_write.c:1082 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452751 RSP: 002b:00007fc658fbbb10 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000000004e RCX: 0000000000452751 RDX: 0000000000000001 RSI: 00007fc658fbbb60 RDI: 0000000000000012 RBP: 00007fc658fbba20 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000004e R11: 0000000000000293 R12: 00000000004b757e R13: 00007fc658fbbb58 R14: 00000000004b758e R15: 0000000000000000 QAT: Invalid ioctl QAT: Invalid ioctl rfkill: input handler disabled rfkill: input handler enabled device gre0 entered promiscuous mode device eql entered promiscuous mode QAT: Invalid ioctl kvm [10793]: vcpu0, guest rIP: 0x9120 disabled perfctr wrmsr: 0xc1 data 0xffffffff QAT: Invalid ioctl kvm [10793]: vcpu0, guest rIP: 0x9122 disabled perfctr wrmsr: 0xc1 data 0xffffffff QAT: Invalid ioctl nla_parse: 10 callbacks suppressed netlink: 1 bytes leftover after parsing attributes in process `syz-executor2'. QAT: Invalid ioctl netlink: 1 bytes leftover after parsing attributes in process `syz-executor2'. QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'.