RDX: 10000000000003ff RSI: 00000000200023c0 RDI: 0000000000000004 RBP: 00007febfef371d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff2676709f R14: 00007febfef37300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 4.14.262-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/24133 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/0xbe0 drivers/tty/serial/8250/8250_port.c:1814 serial8250_handle_irq.part.0+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1901 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1874 [inline] serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1917 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:3257 call_console_drivers kernel/printk/printk.c:1725 [inline] console_unlock+0x99d/0xf20 kernel/printk/printk.c:2407 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:2726 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2807 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.2/24133: #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: 24133 Comm: syz-executor.2 Not tainted 4.14.262-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: 0033:0x7fec005c1fe9 RSP: 002b:00007febfef37168 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fec006d4f60 RCX: 00007fec005c1fe9 RDX: 10000000000003ff RSI: 00000000200023c0 RDI: 0000000000000004 RBP: 00007febfef371d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff2676709f R14: 00007febfef37300 R15: 0000000000022000 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. dccp_xmit_packet: Payload too large (65475) for featneg. dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. dccp_xmit_packet: Payload too large (65475) for featneg. dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue ubi: mtd0 is already attached to ubi0 EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue ubi: mtd0 is already attached to ubi0 EXT4-fs (loop3): mounted filesystem without journal. Opts: ,errors=continue ubi: mtd0 is already attached to ubi0 f2fs_msg: 13 callbacks suppressed F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop3): invalid crc value ubi: mtd0 is already attached to ubi0 F2FS-fs (loop3): Try to recover 2th superblock, ret: 0 F2FS-fs (loop3): Mounted with checkpoint version = 753bd00b ubi: mtd0 is already attached to ubi0 qnx4: no qnx4 filesystem (no root dir). ubi: mtd0 is already attached to ubi0 qnx4: no qnx4 filesystem (no root dir). ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 qnx4: no qnx4 filesystem (no root dir). F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop3): invalid crc value F2FS-fs (loop3): Magic Mismatch, valid(0xf2f52010) - read(0x0) F2FS-fs (loop3): Can't find valid F2FS filesystem in 2th superblock befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop2): cannot parse mount options befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop2): cannot parse mount options print_req_error: I/O error, dev loop2, sector 0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'. net_ratelimit: 13 callbacks suppressed dccp_xmit_packet: Payload too large (65475) for featneg. ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 print_req_error: I/O error, dev loop1, sector 0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options device bridge2 entered promiscuous mode qnx4: no qnx4 filesystem (no root dir). ubi: mtd0 is already attached to ubi0 device bridge3 entered promiscuous mode befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options ubi: mtd0 is already attached to ubi0 device bridge4 entered promiscuous mode ubi: mtd0 is already attached to ubi0 befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options befs: Unrecognized mount option "/dev/ptmx" or missing value qnx4: no qnx4 filesystem (no root dir). befs: (loop1): cannot parse mount options befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options qnx4: no qnx4 filesystem (no root dir). netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'. befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options befs: Unrecognized mount option "/dev/ptmx" or missing value befs: (loop1): cannot parse mount options ubi: mtd0 is already attached to ubi0 befs: Unrecognized mount option "/dev/ptmx" or missing value qnx4: no qnx4 filesystem (no root dir). befs: (loop1): cannot parse mount options ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 ubi: mtd0 is already attached to ubi0 dccp_xmit_packet: Payload too large (65475) for featneg. qnx4: no qnx4 filesystem (no root dir). print_req_error: I/O error, dev loop1, sector 0 qnx4: no qnx4 filesystem (no root dir). dccp_xmit_packet: Payload too large (65475) for featneg. print_req_error: I/O error, dev loop1, sector 0 qnx4: no qnx4 filesystem (no root dir).