RDX: 0000000020000100 RSI: 0000000000005412 RDI: 0000000000000004 RBP: 00007fbc3c4f21d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd5e37d30f R14: 00007fbc3c4f2300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 4.14.288-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/10248 is trying to acquire lock: (console_owner){-...}, at: [] log_next kernel/printk/printk.c:495 [inline] (console_owner){-...}, at: [] console_unlock+0x307/0xf20 kernel/printk/printk.c:2396 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/0xc70 drivers/tty/serial/8250/8250_port.c:1828 serial8250_handle_irq.part.0+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1915 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1888 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1931 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+0xed/0x240 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 arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0xa3/0xe0 kernel/locking/spinlock.c:192 spin_unlock_irqrestore include/linux/spinlock.h:372 [inline] uart_write+0x2dd/0x560 drivers/tty/serial/serial_core.c:632 do_output_char+0x4f5/0x750 drivers/tty/n_tty.c:447 process_output drivers/tty/n_tty.c:514 [inline] n_tty_write+0x3e3/0xda0 drivers/tty/n_tty.c:2345 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 drivers/tty/tty_io.c:1043 redirected_tty_write+0x9c/0xb0 drivers/tty/tty_io.c:1064 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 -> #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+0x7d5/0xa10 drivers/tty/serial/8250/8250_port.c:3271 call_console_drivers kernel/printk/printk.c:1727 [inline] console_unlock+0x99d/0xf20 kernel/printk/printk.c:2409 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 register_console+0x6f4/0xad0 kernel/printk/printk.c:2728 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2809 start_kernel+0x521/0x763 init/main.c:638 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_lock_spinning_enable kernel/printk/printk.c:1590 [inline] console_unlock+0x36f/0xf20 kernel/printk/printk.c:2406 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 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:268 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:313 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 tty_put_char+0xfe/0x120 drivers/tty/tty_io.c:2885 __process_echoes+0x48c/0x8c0 drivers/tty/n_tty.c:728 flush_echoes drivers/tty/n_tty.c:829 [inline] __receive_buf drivers/tty/n_tty.c:1648 [inline] n_tty_receive_buf_common+0x9a3/0x25a0 drivers/tty/n_tty.c:1742 tiocsti drivers/tty/tty_io.c:2185 [inline] tty_ioctl+0xe8a/0x1430 drivers/tty/tty_io.c:2572 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 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 *** 6 locks held by syz-executor.3/10248: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&port->buf.lock/1){+.+.}, at: [] tiocsti drivers/tty/tty_io.c:2183 [inline] #1: (&port->buf.lock/1){+.+.}, at: [] tty_ioctl+0xe20/0x1430 drivers/tty/tty_io.c:2572 #2: (&o_tty->termios_rwsem/1){++++}, at: [] isig+0x36d/0x420 drivers/tty/n_tty.c:1152 #3: (&ldata->output_lock){+.+.}, at: [] flush_echoes drivers/tty/n_tty.c:827 [inline] #3: (&ldata->output_lock){+.+.}, at: [] __receive_buf drivers/tty/n_tty.c:1648 [inline] #3: (&ldata->output_lock){+.+.}, at: [] n_tty_receive_buf_common+0x965/0x25a0 drivers/tty/n_tty.c:1742 #4: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 #5: (console_lock){+.+.}, at: [] vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 stack backtrace: CPU: 1 PID: 10248 Comm: syz-executor.3 Not tainted 4.14.288-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 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_lock_spinning_enable kernel/printk/printk.c:1590 [inline] console_unlock+0x36f/0xf20 kernel/printk/printk.c:2406 vprintk_emit+0x224/0x620 kernel/printk/printk.c:1925 vprintk_func+0x58/0x160 kernel/printk/printk_safe.c:409 printk+0x9e/0xbc kernel/printk/printk.c:1998 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:268 tty_insert_flip_string_fixed_flag+0x8b/0x210 drivers/tty/tty_buffer.c:313 tty_insert_flip_string include/linux/tty_flip.h:37 [inline] pty_write+0x10d/0x1d0 drivers/tty/pty.c:122 tty_put_char+0xfe/0x120 drivers/tty/tty_io.c:2885 __process_echoes+0x48c/0x8c0 drivers/tty/n_tty.c:728 flush_echoes drivers/tty/n_tty.c:829 [inline] __receive_buf drivers/tty/n_tty.c:1648 [inline] n_tty_receive_buf_common+0x9a3/0x25a0 drivers/tty/n_tty.c:1742 tiocsti drivers/tty/tty_io.c:2185 [inline] tty_ioctl+0xe8a/0x1430 drivers/tty/tty_io.c:2572 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fbc3db7d109 RSP: 002b:00007fbc3c4f2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fbc3dc8ff60 RCX: 00007fbc3db7d109 RDX: 0000000020000100 RSI: 0000000000005412 RDI: 0000000000000004 RBP: 00007fbc3c4f21d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd5e37d30f R14: 00007fbc3c4f2300 R15: 0000000000022000 raw_sendmsg: syz-executor.1 forgot to set AF_INET. Fix it! syz-executor.5 uses obsolete (PF_INET,SOCK_PACKET) netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 IPv6: ADDRCONF(NETDEV_UP): veth3: link is not ready CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=ffffffffffffe871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000000 RIP = 0x0000000000000000 RFLAGS=0x00020a02 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 Interruptibility = 00000000 ActivityState = 00000000 *** Host State *** RIP = 0xffffffff81160e2e RSP = 0xffff8880a95af9b8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007f1af5638700 GSBase=ffff8880ba500000 TRBase=fffffe0000003000 GDTBase=fffffe0000001000 IDTBase=fffffe0000000000 CR0=0000000080050033 CR3=00000000a0057000 CR4=00000000003426e0 Sysenter RSP=fffffe0000003000 CS:RIP=0010:ffffffff87401690 EFER = 0x0000000000000d01 PAT = 0x0407050600070106 *** Control State *** PinBased=0000003f CPUBased=b6a1edfa SecondaryExec=000000e3 EntryControls=0000d1ff ExitControls=002fefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=800000c0 errcode=00000000 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000000 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffb29999926e TPR Threshold = 0x00 EPT pointer = 0x00000000a075a01e Virtual processor ID = 0x0001 block nbd0: shutting down sockets unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop0): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1)