WARNING: possible circular locking dependency detected 4.14.212-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/21168 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+0xf0/0x246 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+0x58/0x152 kernel/printk/printk_safe.c:401 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+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x154 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 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:2186 [inline] tty_ioctl+0xe5a/0x13c0 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 *** 4 locks held by syz-executor.4/21168: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&o_tty->termios_rwsem/1){++++}, at: [] isig+0x36d/0x420 drivers/tty/n_tty.c:1152 #2: (&ldata->output_lock){+.+.}, at: [] flush_echoes drivers/tty/n_tty.c:827 [inline] #2: (&ldata->output_lock){+.+.}, at: [] __receive_buf drivers/tty/n_tty.c:1648 [inline] #2: (&ldata->output_lock){+.+.}, at: [] n_tty_receive_buf_common+0x965/0x25a0 drivers/tty/n_tty.c:1742 #3: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 stack backtrace: CPU: 1 PID: 21168 Comm: syz-executor.4 Not tainted 4.14.212-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+0x1b2/0x283 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+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x154 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 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:2186 [inline] tty_ioctl+0xe5a/0x13c0 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: 0033:0x45e149 RSP: 002b:00007f08c7c00c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 000000000045e149 RDX: 0000000020000100 RSI: 0000000000005412 RDI: 0000000000000006 RBP: 00007f08c7c00ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff19a5a2af R14: 00007f08c7c019c0 R15: 000000000119bf8c FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) kauditd_printk_skb: 14 callbacks suppressed audit: type=1800 audit(1608354572.028:110): pid=21277 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16731 res=0 FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354572.188:111): pid=21297 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16730 res=0 FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354573.118:112): pid=21390 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16691 res=0 FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354573.148:113): pid=21390 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16691 res=0 FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354573.828:114): pid=21428 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16723 res=0 FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354573.848:115): pid=21428 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16723 res=0 audit: type=1800 audit(1608354573.978:116): pid=21459 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16699 res=0 audit: type=1800 audit(1608354573.998:117): pid=21459 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16699 res=0 FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354574.068:118): pid=21477 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16718 res=0 FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354574.098:119): pid=21477 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16718 res=0 FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor.4'. FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) ptrace attach of "/root/syz-executor.4"[8005] was attempted by "/root/syz-executor.4"[21859] ptrace attach of "/root/syz-executor.4"[8005] was attempted by "/root/syz-executor.4"[21867] FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop5): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) kauditd_printk_skb: 56 callbacks suppressed audit: type=1804 audit(1608354577.098:176): pid=22104 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir492619558/syzkaller.CVlgcv/501/bus" dev="sda1" ino=16780 res=1 audit: type=1804 audit(1608354577.098:177): pid=22104 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir492619558/syzkaller.CVlgcv/501/bus" dev="sda1" ino=16780 res=1 audit: type=1800 audit(1608354577.228:178): pid=22124 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16779 res=0 FAT-fs (loop3): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1800 audit(1608354577.348:179): pid=22148 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16695 res=0 audit: type=1800 audit(1608354577.448:180): pid=22170 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16749 res=0 audit: type=1800 audit(1608354577.508:181): pid=22187 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16723 res=0 audit: type=1800 audit(1608354577.508:182): pid=22187 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16723 res=0 audit: type=1800 audit(1608354577.618:183): pid=22206 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16699 res=0 audit: type=1800 audit(1608354577.628:184): pid=22206 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16699 res=0 audit: type=1800 audit(1608354577.698:185): pid=22228 uid=0 auid=0 ses=4 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16195 res=0 caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect