ebt_limit: overflow, try lower: 570423552/0 audit: type=1800 audit(1611341194.726:80): pid=12076 uid=0 auid=0 ses=4 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="file0" dev="sda1" ino=16015 res=0 audit: type=1804 audit(1611341194.756:81): pid=12076 uid=0 auid=0 ses=4 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir562845653/syzkaller.BtuLzc/61/file0" dev="sda1" ino=16015 res=1 ttyprintk ttyprintk: tty_port_close_start: tty->count = 1 port count = 2 ====================================================== WARNING: possible circular locking dependency detected 4.19.169-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/12067 is trying to acquire lock: 000000005ad8cb9c (console_owner){-...}, at: console_trylock_spinning kernel/printk/printk.c:1697 [inline] 000000005ad8cb9c (console_owner){-...}, at: vprintk_emit+0x3fe/0x740 kernel/printk/printk.c:1964 but task is already holding lock: 00000000f4553dda (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x28/0x540 drivers/tty/tty_port.c:574 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(&port->lock)->rlock){-.-.}: tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x490/0xaf0 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x31f/0x3d0 drivers/tty/serial/8250/8250_port.c:1893 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1866 [inline] serial8250_default_handle_irq+0xae/0x220 drivers/tty/serial/8250/8250_port.c:1909 serial8250_interrupt+0x101/0x240 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x27e/0x8e0 kernel/irq/handle.c:149 handle_irq_event_percpu kernel/irq/handle.c:189 [inline] handle_irq_event+0x102/0x290 kernel/irq/handle.c:206 handle_edge_irq+0x260/0xcf0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1c0 arch/x86/kernel/irq.c:246 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+0x49/0x310 arch/x86/kernel/process.c:557 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x2ec/0x4b0 kernel/sched/idle.c:263 cpu_startup_entry+0xc5/0xe0 kernel/sched/idle.c:369 start_kernel+0x8d6/0x911 init/main.c:736 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&port_lock_key){-.-.}: serial8250_console_write+0x89b/0xad0 drivers/tty/serial/8250/8250_port.c:3270 call_console_drivers kernel/printk/printk.c:1764 [inline] console_unlock+0xbb6/0x1110 kernel/printk/printk.c:2460 vprintk_emit+0x2d1/0x740 kernel/printk/printk.c:1965 vprintk_func+0x79/0x180 kernel/printk/printk_safe.c:397 printk+0xba/0xed kernel/printk/printk.c:2040 register_console+0x87f/0xc90 kernel/printk/printk.c:2776 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:684 console_init+0x4cb/0x718 kernel/printk/printk.c:2862 start_kernel+0x686/0x911 init/main.c:659 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-...}: console_trylock_spinning kernel/printk/printk.c:1718 [inline] vprintk_emit+0x43b/0x740 kernel/printk/printk.c:1964 vprintk_func+0x79/0x180 kernel/printk/printk_safe.c:397 printk+0xba/0xed kernel/printk/printk.c:2040 tty_port_close_start.part.0+0x4f3/0x540 drivers/tty/tty_port.c:576 tty_port_close_start drivers/tty/tty_port.c:648 [inline] tty_port_close+0x46/0x160 drivers/tty/tty_port.c:641 tty_release+0x45e/0x1210 drivers/tty/tty_io.c:1678 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbed/0x2be0 kernel/exit.c:890 do_group_exit+0x125/0x310 kernel/exit.c:993 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe 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 *** 2 locks held by syz-executor.3/12067: #0: 00000000f0ef3019 (&tty->legacy_mutex){+.+.}, at: tty_lock+0x6a/0xa0 drivers/tty/tty_mutex.c:19 #1: 00000000f4553dda (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x28/0x540 drivers/tty/tty_port.c:574 stack backtrace: CPU: 0 PID: 12067 Comm: syz-executor.3 Not tainted 4.19.169-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1865 [inline] check_prevs_add kernel/locking/lockdep.c:1978 [inline] validate_chain kernel/locking/lockdep.c:2419 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907 console_trylock_spinning kernel/printk/printk.c:1718 [inline] vprintk_emit+0x43b/0x740 kernel/printk/printk.c:1964 vprintk_func+0x79/0x180 kernel/printk/printk_safe.c:397 printk+0xba/0xed kernel/printk/printk.c:2040 tty_port_close_start.part.0+0x4f3/0x540 drivers/tty/tty_port.c:576 tty_port_close_start drivers/tty/tty_port.c:648 [inline] tty_port_close+0x46/0x160 drivers/tty/tty_port.c:641 tty_release+0x45e/0x1210 drivers/tty/tty_io.c:1678 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xbed/0x2be0 kernel/exit.c:890 do_group_exit+0x125/0x310 kernel/exit.c:993 get_signal+0x3f2/0x1f70 kernel/signal.c:2589 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45e219 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f195e9bfc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000003 RBX: 0000000000000004 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 0000000020000040 RDI: ffffffffffffff9c RBP: 000000000119bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffc7ebc20cf R14: 00007f195e9c09c0 R15: 000000000119bf8c blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue blktrace: Concurrent blktraces are not allowed on loop0 EXT4-fs (loop2): mounted filesystem without journal. Opts: ,errors=continue blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit_mt_check: 33 callbacks suppressed ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit_mt_check: 57 callbacks suppressed ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 blktrace: Concurrent blktraces are not allowed on loop0 blktrace: Concurrent blktraces are not allowed on loop0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 ebt_limit: overflow, try lower: 570423552/0 netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'.