RBP: 00007fd53cc8f1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffde887529f R14: 00007fd53cc8f300 R15: 0000000000022000 CPU: 1 PID: 29811 Comm: syz-executor.2 Not tainted 4.14.231-syzkaller #0 ====================================================== WARNING: possible circular locking dependency detected 4.14.231-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/29809 is trying to acquire lock: (console_owner){-...}, at: [] console_trylock_spinning kernel/printk/printk.c:1658 [inline] (console_owner){-...}, at: [] vprintk_emit+0x32a/0x620 kernel/printk/printk.c:1922 but task is already holding lock: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:46 serial8250_tx_chars+0x3fe/0xbf0 drivers/tty/serial/8250/8250_port.c:1810 serial8250_handle_irq.part.0+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1897 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1870 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1913 serial8250_interrupt+0xf3/0x210 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0xee/0x7f0 kernel/irq/handle.c:147 handle_irq_event_percpu kernel/irq/handle.c:187 [inline] handle_irq_event+0xf0/0x250 kernel/irq/handle.c:204 handle_edge_irq+0x224/0xc40 kernel/irq/chip.c:770 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230 ret_from_intr+0x0/0x1e native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:558 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x750/0x770 init/main.c:708 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 serial8250_console_write+0x7a7/0x9d0 drivers/tty/serial/8250/8250_port.c:3253 call_console_drivers kernel/printk/printk.c:1725 [inline] console_unlock+0x99d/0xf20 kernel/printk/printk.c:2400 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1923 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1996 register_console+0x6f4/0xad0 kernel/printk/printk.c:2719 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2800 start_kernel+0x52e/0x770 init/main.c:634 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #0 (console_owner){-...}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_trylock_spinning kernel/printk/printk.c:1679 [inline] vprintk_emit+0x367/0x620 kernel/printk/printk.c:1922 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x6d/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] tty_buffer_alloc+0xc0/0x270 drivers/tty/tty_buffer.c:169 __tty_buffer_request_room+0x12c/0x290 drivers/tty/tty_buffer.c:267 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:312 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 n_tty_write+0x85e/0xda0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 do_loop_readv_writev fs/read_write.c:698 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_write+0x3da/0x550 fs/read_write.c:956 vfs_writev+0x125/0x290 fs/read_write.c:999 do_writev+0xfc/0x2c0 fs/read_write.c:1034 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &(&port->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&port->lock)->rlock); lock(&port_lock_key); lock(&(&port->lock)->rlock); lock(console_owner); *** DEADLOCK *** 5 locks held by syz-executor.3/29809: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write_lock drivers/tty/tty_io.c:885 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] do_tty_write drivers/tty/tty_io.c:908 [inline] #1: (&tty->atomic_write_lock){+.+.}, at: [] tty_write+0x22d/0x740 drivers/tty/tty_io.c:1043 #2: (&tty->termios_rwsem){++++}, at: [] n_tty_write+0x18a/0xda0 drivers/tty/n_tty.c:2316 #3: (&ldata->output_lock){+.+.}, at: [] n_tty_write+0x82b/0xda0 drivers/tty/n_tty.c:2355 #4: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 stack backtrace: CPU: 0 PID: 29809 Comm: syz-executor.3 Not tainted 4.14.231-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 console_trylock_spinning kernel/printk/printk.c:1679 [inline] vprintk_emit+0x367/0x620 kernel/printk/printk.c:1922 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x6d/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] tty_buffer_alloc+0xc0/0x270 drivers/tty/tty_buffer.c:169 __tty_buffer_request_room+0x12c/0x290 drivers/tty/tty_buffer.c:267 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:312 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 n_tty_write+0x85e/0xda0 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 do_loop_readv_writev fs/read_write.c:698 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_write+0x3da/0x550 fs/read_write.c:956 vfs_writev+0x125/0x290 fs/read_write.c:999 do_writev+0xfc/0x2c0 fs/read_write.c:1034 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fd53cc8f188 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000001 RSI: 0000000020002980 RDI: 0000000000000004 RBP: 00007fd53cc8f1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffde887529f R14: 00007fd53cc8f300 R15: 0000000000022000 nla_parse: 7 callbacks suppressed netlink: 76 bytes leftover after parsing attributes in process `syz-executor.4'. 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+0x1b2/0x281 lib/dump_stack.c:58 tc_ctl_action: received NO action attribs fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/0x149 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc_node mm/slab.c:3297 [inline] kmem_cache_alloc_node_trace+0x25a/0x400 mm/slab.c:3659 __do_kmalloc_node mm/slab.c:3681 [inline] __kmalloc_node_track_caller+0x38/0x70 mm/slab.c:3696 __kmalloc_reserve net/core/skbuff.c:137 [inline] __alloc_skb+0x96/0x510 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1159 [inline] netlink_sendmsg+0x901/0xb80 net/netlink/af_netlink.c:1853 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'. bond32 (uninitialized): Released all slaves __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fb77e72e188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fb77e72e1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc87d819ff R14: 00007fb77e72e300 R15: 0000000000022000 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. tc_ctl_action: received NO action attribs netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 28 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.2'. bond43 (uninitialized): Released all slaves netlink: 76 bytes leftover after parsing attributes in process `syz-executor.4'. tc_ctl_action: received NO action attribs netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 28 bytes leftover after parsing attributes in process `syz-executor.4'. bond40 (uninitialized): Released all slaves tc_ctl_action: received NO action attribs tc_ctl_action: received NO action attribs bond44 (uninitialized): Released all slaves VFS: unable to find oldfs superblock on device loop2 cramfs: wrong magic cramfs: wrong magic bond42 (uninitialized): Released all slaves nla_parse: 28 callbacks suppressed netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.0'. REISERFS warning (device loop2): super-6502 reiserfs_getopt: unknown mount option "hash=r5" REISERFS warning (device loop2): super-6502 reiserfs_getopt: unknown mount option "hash=r5" divide error: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 30962 Comm: syz-executor.2 Not tainted 4.14.231-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888041d78080 task.stack: ffff88803c688000 RIP: 0010:fbcon_init+0xcb4/0x1cc0 drivers/video/fbdev/core/fbcon.c:1065 RSP: 0018:ffff88803c68f7e0 EFLAGS: 00010246 RAX: 00000000000001e0 RBX: ffff8880b090cac0 RCX: ffffc900098d0000 RDX: 0000000000000000 RSI: ffff8880921167f4 RDI: ffff8880b090cc78 RBP: ffff888092116440 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888041d78080 R12: ffff888238884880 R13: 0000000000000000 R14: ffff888092116774 R15: 00000000000001e0 FS: 00007fb77e70d700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff22a3bd27 CR3: 0000000047099000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: visual_init+0x332/0x5e0 drivers/tty/vt/vt.c:746 vc_allocate+0x2c5/0x640 drivers/tty/vt/vt.c:802 con_install+0x4d/0x450 drivers/tty/vt/vt.c:2899 tty_driver_install_tty drivers/tty/tty_io.c:1225 [inline] tty_init_dev.part.0+0x99/0x400 drivers/tty/tty_io.c:1338 tty_init_dev drivers/tty/tty_io.c:1328 [inline] tty_open_by_driver drivers/tty/tty_io.c:1973 [inline] tty_open+0x669/0x8b0 drivers/tty/tty_io.c:2021 chrdev_open+0x23c/0x6d0 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0x628/0x2970 fs/namei.c:3569 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x419544 RSP: 002b:00007fb77e70ccc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000419544 RDX: 0000000000000002 RSI: 00007fb77e70cd60 RDI: 00000000ffffff9c RBP: 00007fb77e70cd60 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 R13: 00007ffc87d819ff R14: 00007fb77e70d300 R15: 0000000000022000 Code: 54 24 30 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 8d 0d 00 00 31 d2 44 89 f8 48 8b 74 24 38 b5 b0 03 00 00 48 89 f2 48 c1 ea 03 89 44 24 30 48 b8 00 00 RIP: fbcon_init+0xcb4/0x1cc0 drivers/video/fbdev/core/fbcon.c:1065 RSP: ffff88803c68f7e0 ---[ end trace accdaf8af353d788 ]---