====================================================== WARNING: possible circular locking dependency detected 4.13.0-next-20170912+ #20 Not tainted ------------------------------------------------------ syz-executor5/10329 is trying to acquire lock: (console_lock){+.+.}, at: [] vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:218 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:66 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:74 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&pipe->mutex/1){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 pipe_lock_nested fs/pipe.c:66 [inline] pipe_lock+0x56/0x70 fs/pipe.c:74 iter_file_splice_write+0x264/0xf50 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/0xbe -> #2 (sb_writers){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:35 [inline] percpu_down_read include/linux/percpu-rwsem.h:58 [inline] __sb_start_write+0x18f/0x290 fs/super.c:1341 sb_start_write include/linux/fs.h:1541 [inline] mnt_want_write+0x3f/0xb0 fs/namespace.c:387 filename_create+0x12b/0x520 fs/namei.c:3628 kern_path_create+0x33/0x40 fs/namei.c:3674 handle_create+0xc0/0x760 drivers/base/devtmpfs.c:203 -> #1 ((complete)&req.done){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 complete_acquire include/linux/completion.h:39 [inline] __wait_for_common kernel/sched/completion.c:108 [inline] wait_for_common kernel/sched/completion.c:122 [inline] wait_for_completion+0xc8/0x770 kernel/sched/completion.c:143 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:628 vc_allocate+0x4b7/0x6b0 drivers/tty/vt/vt.c:795 con_install+0x52/0x440 drivers/tty/vt/vt.c:2876 tty_driver_install_tty drivers/tty/tty_io.c:1214 [inline] tty_init_dev+0xf6/0x4a0 drivers/tty/tty_io.c:1314 tty_open_by_driver drivers/tty/tty_io.c:1941 [inline] tty_open+0x60f/0xac0 drivers/tty/tty_io.c:1989 chrdev_open+0x257/0x730 fs/char_dev.c:416 do_dentry_open+0x67f/0xd70 fs/open.c:752 vfs_open+0x107/0x230 fs/open.c:866 do_last fs/namei.c:3387 [inline] path_openat+0x1157/0x3520 fs/namei.c:3527 do_filp_open+0x25b/0x3b0 fs/namei.c:3562 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/0xbe -> #0 (console_lock){+.+.}: check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:218 do_loop_readv_writev fs/read_write.c:693 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:917 vfs_readv+0x121/0x1c0 fs/read_write.c:979 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/0xbe 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-executor5/10329: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:66 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 fs/pipe.c:74 stack backtrace: CPU: 1 PID: 10329 Comm: syz-executor5 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_circular_bug+0x503/0x710 kernel/locking/lockdep.c:1259 check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 console_lock+0x4b/0x80 kernel/printk/printk.c:2047 vcs_read+0x129/0xae0 drivers/tty/vt/vc_screen.c:218 do_loop_readv_writev fs/read_write.c:693 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:917 vfs_readv+0x121/0x1c0 fs/read_write.c:979 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/0xbe RIP: 0033:0x451e59 RSP: 002b:00007f82a10a5c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00000000007180b0 RCX: 0000000000451e59 RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000017 RBP: 0000000000000082 R08: 000000005636d6e4 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b7397 R13: 00000000ffffffff R14: 00000000000000fb R15: fffffffffffffffc TCP: request_sock_TCP: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. netlink: 8 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor0'. kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns sctp: [Deprecated]: syz-executor2 (pid 10489) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor2 (pid 10499) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead netlink: 5 bytes leftover after parsing attributes in process `syz-executor7'. kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns kvm: vcpu 0: requested 68374 ns lapic timer period limited to 500000 ns QAT: Invalid ioctl QAT: Invalid ioctl SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8 sclass=netlink_route_socket pig=10725 comm=syz-executor5 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8 sclass=netlink_route_socket pig=10725 comm=syz-executor5 QAT: Invalid ioctl QAT: Invalid ioctl PF_BRIDGE: RTM_NEWNEIGH with invalid ifindex PF_BRIDGE: RTM_NEWNEIGH with invalid ifindex kvm [10809]: vcpu0, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 kvm [10809]: vcpu0, guest rIP: 0xfff0 disabled perfctr wrmsr: 0x186 data 0x8 netlink: 11 bytes leftover after parsing attributes in process `syz-executor3'. nla_parse: 1 callbacks suppressed netlink: 37 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 37 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 11839 Comm: syz-executor0 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:31 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc_node mm/slab.c:3304 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3649 __alloc_skb+0xf1/0x740 net/core/skbuff.c:194 alloc_skb include/linux/skbuff.h:976 [inline] pfkey_sendmsg+0x20f/0x9f0 net/key/af_key.c:3635 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x320/0x5e0 net/socket.c:912 call_write_iter include/linux/fs.h:1770 [inline] new_sync_write fs/read_write.c:468 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:481 vfs_write+0x18f/0x510 fs/read_write.c:543 SYSC_write fs/read_write.c:588 [inline] SyS_write+0xef/0x220 fs/read_write.c:580 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x451e59 RSP: 002b:00007f16d1783c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 0000000000000010 RSI: 000000002004b000 RDI: 0000000000000005 RBP: 00007f16d1783a10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b69f7 R13: 00007f16d1783b48 R14: 00000000004b6a07 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 11858 Comm: syz-executor3 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:31 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc_node mm/slab.c:3304 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3649 __alloc_skb+0xf1/0x740 net/core/skbuff.c:194 alloc_skb include/linux/skbuff.h:976 [inline] pfkey_sendmsg+0x20f/0x9f0 net/key/af_key.c:3635 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x320/0x5e0 net/socket.c:912 call_write_iter include/linux/fs.h:1770 [inline] new_sync_write fs/read_write.c:468 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:481 vfs_write+0x18f/0x510 fs/read_write.c:543 SYSC_write fs/read_write.c:588 [inline] SyS_write+0xef/0x220 fs/read_write.c:580 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x451e59 RSP: 002b:00007f4d12385c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 0000000000000010 RSI: 000000002004b000 RDI: 0000000000000005 RBP: 00007f4d12385a10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b69f7 R13: 00007f4d12385b48 R14: 00000000004b6a07 R15: 0000000000000000 netlink: 8 bytes leftover after parsing attributes in process `syz-executor4'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor4'. tc_dump_action: action bad kind netlink: 3 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor4'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor4'. tc_dump_action: action bad kind netlink: 3 bytes leftover after parsing attributes in process `syz-executor3'. 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 0 CPU: 0 PID: 12035 Comm: syz-executor7 Not tainted 4.13.0-next-20170912+ #20 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:31 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc mm/slab.c:3383 [inline] __do_kmalloc mm/slab.c:3723 [inline] __kmalloc+0x63/0x760 mm/slab.c:3734 kmalloc include/linux/slab.h:498 [inline] sock_kmalloc+0x112/0x190 net/core/sock.c:1974 ipv6_sock_mc_join+0x506/0xa80 net/ipv6/mcast.c:158 do_ipv6_setsockopt.isra.12+0x2f11/0x35c0 net/ipv6/ipv6_sockglue.c:636 ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:913 udpv6_setsockopt+0x45/0x80 net/ipv6/udp.c:1451 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2960 SYSC_setsockopt net/socket.c:1852 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1831 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x451e59 RSP: 002b:00007f2c9de61c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 0000000000000014 RSI: 0000000000000029 RDI: 0000000000000005 RBP: 00007f2c9de61a10 R08: 0000000000000014 R09: 0000000000000000 R10: 0000000020599000 R11: 0000000000000216 R12: 00000000004b69f7 R13: 00007f2c9de61b48 R14: 00000000004b6a07 R15: 0000000000000000 nla_parse: 1 callbacks suppressed netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor1'.