RDX: 0000000000000003 RSI: 000000000000540a RDI: 0000000000000005 RBP: 00007f245317bca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc26d2d2ff R14: 00007f245317c9c0 R15: 000000000119bf8c ====================================================== WARNING: possible circular locking dependency detected 4.14.213-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/11022 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_secondary+0x4db/0x670 arch/x86/kernel/smpboot.c:272 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_send_xchar+0x245/0x360 drivers/tty/tty_io.c:1092 n_tty_ioctl_helper+0x145/0x350 drivers/tty/tty_ioctl.c:926 n_tty_ioctl+0x47/0x2e0 drivers/tty/n_tty.c:2466 tty_ioctl+0x5af/0x13c0 drivers/tty/tty_io.c:2670 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.3/11022: #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: [] tty_send_xchar+0x1b5/0x360 drivers/tty/tty_io.c:1086 #2: (&o_tty->termios_rwsem/1){++++}, at: [] tty_send_xchar+0x1e8/0x360 drivers/tty/tty_io.c:1089 #3: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1d0 drivers/tty/pty.c:120 stack backtrace: CPU: 0 PID: 11022 Comm: syz-executor.3 Not tainted 4.14.213-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_send_xchar+0x245/0x360 drivers/tty/tty_io.c:1092 n_tty_ioctl_helper+0x145/0x350 drivers/tty/tty_ioctl.c:926 n_tty_ioctl+0x47/0x2e0 drivers/tty/n_tty.c:2466 tty_ioctl+0x5af/0x13c0 drivers/tty/tty_io.c:2670 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: 0033:0x45e219 RSP: 002b:00007f245317bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219 RDX: 0000000000000003 RSI: 000000000000540a RDI: 0000000000000005 RBP: 00007f245317bca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc26d2d2ff R14: 00007f245317c9c0 R15: 000000000119bf8c CPU: 1 PID: 11017 Comm: syz-executor.2 Not tainted 4.14.213-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 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/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] kmem_cache_alloc_trace+0x29a/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] tty_alloc_file drivers/tty/tty_io.c:186 [inline] tty_open+0x11a/0x8b0 drivers/tty/tty_io.c:2015 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 dentry_open+0xa7/0x210 fs/open.c:905 ptm_open_peer+0x185/0x240 drivers/tty/pty.c:647 tty_ioctl+0x8a3/0x13c0 drivers/tty/tty_io.c:2654 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: 0033:0x45e219 RSP: 002b:00007fb53a8c2c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000000005441 RDI: 0000000000000003 RBP: 00007fb53a8c2ca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffd1d52b23f R14: 00007fb53a8c39c0 R15: 000000000119bf8c CPU: 0 PID: 11020 Comm: syz-executor.5 Not tainted 4.14.213-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 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0x10a/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] kmem_cache_alloc_trace+0x29a/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] tty_alloc_file drivers/tty/tty_io.c:186 [inline] tty_open+0x11a/0x8b0 drivers/tty/tty_io.c:2015 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 dentry_open+0xa7/0x210 fs/open.c:905 ptm_open_peer+0x185/0x240 drivers/tty/pty.c:647 tty_ioctl+0x8a3/0x13c0 drivers/tty/tty_io.c:2654 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: 0033:0x45e219 RSP: 002b:00007fd3dafeec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000000005441 RDI: 0000000000000003 RBP: 00007fd3dafeeca0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007fff0a36a5bf R14: 00007fd3dafef9c0 R15: 000000000119bf8c print_req_error: I/O error, dev loop1, sector 0 print_req_error: I/O error, dev loop1, sector 0 Buffer I/O error on dev loop1, logical block 0, async page read block nbd5: NBD_DISCONNECT block nbd5: shutting down sockets block nbd5: NBD_DISCONNECT print_req_error: I/O error, dev loop1, sector 0 block nbd5: Send disconnect failed -32 block nbd5: shutting down sockets ufs: ufs was compiled with read-only support, can't be mounted as read-write FAT-fs (loop2): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1804 audit(1609965782.380:22): pid=11149 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir069974743/syzkaller.qbDxRp/58/file0/bus" dev="loop2" ino=3 res=1 audit: type=1804 audit(1609965782.450:23): pid=11165 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir069974743/syzkaller.qbDxRp/58/file0/bus" dev="loop2" ino=3 res=1 FAT-fs (loop2): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) audit: type=1804 audit(1609965783.260:24): pid=11189 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir769260539/syzkaller.4IMLbt/76/bus" dev="sda1" ino=15922 res=1 FAT-fs (loop0): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop1): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) block nbd4: NBD_DISCONNECT audit: type=1804 audit(1609965783.430:25): pid=11206 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir590890319/syzkaller.NALw5p/72/file0/bus" dev="loop0" ino=5 res=1 block nbd4: shutting down sockets block nbd5: shutting down sockets audit: type=1804 audit(1609965783.480:26): pid=11211 uid=0 auid=0 ses=4 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir805495308/syzkaller.WxAy6t/40/file0/bus" dev="loop1" ino=6 res=1 block nbd5: shutting down sockets FAT-fs (loop0): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) FAT-fs (loop1): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1) block nbd4: shutting down sockets block nbd4: shutting down sockets block nbd4: shutting down sockets block nbd4: shutting down sockets mkiss: ax0: crc mode is auto. block nbd4: shutting down sockets mkiss: ax0: crc mode is auto. block nbd4: shutting down sockets block nbd5: NBD_DISCONNECT block nbd5: shutting down sockets block nbd5: NBD_DISCONNECT block nbd5: Device being setup by another task block nbd3: NBD_DISCONNECT block nbd4: shutting down sockets block nbd5: shutting down sockets block nbd3: shutting down sockets block nbd4: shutting down sockets block nbd3: NBD_DISCONNECT block nbd3: shutting down sockets mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. block nbd2: NBD_DISCONNECT mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. raw_sendmsg: syz-executor.5 forgot to set AF_INET. Fix it! mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. block nbd4: Device being setup by another task mkiss: ax0: crc mode is auto. block nbd4: shutting down sockets block nbd4: Device being setup by another task block nbd4: shutting down sockets block nbd4: shutting down sockets block nbd4: shutting down sockets mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. block nbd2: shutting down sockets block nbd5: NBD_DISCONNECT block nbd5: shutting down sockets block nbd5: NBD_DISCONNECT block nbd5: Send disconnect failed -32 block nbd5: shutting down sockets mkiss: ax0: crc mode is auto. mkiss: ax0: crc mode is auto. block nbd3: shutting down sockets block nbd4: shutting down sockets block nbd5: shutting down sockets block nbd4: shutting down sockets block nbd5: shutting down sockets block nbd2: shutting down sockets block nbd2: shutting down sockets block nbd3: shutting down sockets block nbd4: NBD_DISCONNECT block nbd3: Device being setup by another task block nbd3: shutting down sockets block nbd4: shutting down sockets block nbd4: NBD_DISCONNECT block nbd4: shutting down sockets block nbd3: NBD_DISCONNECT block nbd3: shutting down sockets audit: type=1804 audit(1609965789.570:27): pid=12426 uid=0 auid=0 ses=4 op="invalid_pcr" cause="ToMToU" comm="syz-executor.4" name="/root/syzkaller-testdir769260539/syzkaller.4IMLbt/113/bus" dev="sda1" ino=15994 res=1 block nbd3: NBD_DISCONNECT block nbd3: shutting down sockets block nbd5: NBD_DISCONNECT block nbd4: shutting down sockets block nbd5: shutting down sockets block nbd4: shutting down sockets block nbd5: NBD_DISCONNECT block nbd2: NBD_DISCONNECT block nbd5: shutting down sockets block nbd2: shutting down sockets block nbd2: NBD_DISCONNECT block nbd2: Send disconnect failed -32 block nbd4: shutting down sockets block nbd2: shutting down sockets block nbd4: shutting down sockets