WARNING: locking bug in __up_console_sem

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2f166cdc Linux 4.14.196
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13e19e3e900000
kernel config: https://syzkaller.appspot.com/x/.config?x=e2677667b00dfecb
dashboard link: https://syzkaller.appspot.com/bug?extid=a8b67b20744ce13866e0
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14cd52a5900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=160016a5900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a8b67b...@syzkaller.appspotmail.com

DEBUG_LOCKS_WARN_ON(depth <= 0)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9859 at kernel/locking/lockdep.c:3760 __lock_release kernel/locking/lockdep.c:3760 [inline]
WARNING: CPU: 0 PID: 9859 at kernel/locking/lockdep.c:3760 lock_release.cold+0x13/0xbf kernel/locking/lockdep.c:4017
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 9859 Comm: syz-executor186 Not tainted 4.14.196-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
panic+0x1f9/0x42d kernel/panic.c:183
__warn.cold+0x20/0x4b kernel/panic.c:547
report_bug+0x208/0x249 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:__lock_release kernel/locking/lockdep.c:3760 [inline]
RIP: 0010:lock_release.cold+0x13/0xbf kernel/locking/lockdep.c:4017
RSP: 0018:ffff8880001273f0 EFLAGS: 00010082
RAX: 000000000000001f RBX: 1ffff11000024e81 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000f6 RDI: ffffed1000024e74
RBP: ffffffff87d7c880 R08: 000000000000001f R09: ffffed1015d442f7
R10: ffff8880aea217be R11: ffff888000118140 R12: ffffffff8348237f
R13: ffffffff8a5a5c00 R14: ffff888000118140 R15: 0000000000000000
__up_console_sem+0x1e/0x1b0 kernel/printk/printk.c:242
console_unlock+0x531/0xf20 kernel/printk/printk.c:2419
do_con_write+0xb2f/0x19b0 drivers/tty/vt/vt.c:2459
con_write+0x21/0xa0 drivers/tty/vt/vt.c:2805
process_output_block drivers/tty/n_tty.c:595 [inline]
n_tty_write+0x352/0xda0 drivers/tty/n_tty.c:2333
do_tty_write drivers/tty/tty_io.c:959 [inline]
tty_write+0x410/0x740 drivers/tty/tty_io.c:1043
__vfs_write+0xe4/0x630 fs/read_write.c:480
__kernel_write+0xf5/0x330 fs/read_write.c:501
write_pipe_buf+0x143/0x1c0 fs/splice.c:797
splice_from_pipe_feed fs/splice.c:502 [inline]
__splice_from_pipe+0x326/0x7a0 fs/splice.c:626
splice_from_pipe fs/splice.c:661 [inline]
default_file_splice_write+0xc5/0x150 fs/splice.c:809
do_splice_from fs/splice.c:851 [inline]
direct_splice_actor+0x115/0x160 fs/splice.c:1018
splice_direct_to_actor+0x27c/0x730 fs/splice.c:973
do_splice_direct+0x164/0x210 fs/splice.c:1061
do_sendfile+0x47f/0xb30 fs/read_write.c:1441
SYSC_sendfile64 fs/read_write.c:1502 [inline]
SyS_sendfile64+0xff/0x110 fs/read_write.c:1488
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x446f99
RSP: 002b:00007fb7a52ced18 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000006dcc58 RCX: 0000000000446f99
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00000000006dcc50 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 0800000080004101 R11: 0000000000000246 R12: 00000000006dcc5c
R13: 00007fb7a52ced20 R14: 00007fb7a52ced20 R15: 20c49ba5e353f7cf
Kernel Offset: disabled


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