diff options
| author | Matthias Reichl <hias@horus.com> | 2020-11-05 13:34:32 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-06 17:24:49 +0100 |
| commit | 4466d6d2f80c1193e0845d110277c56da77a6418 (patch) | |
| tree | f5814b105f5b9cf07ae532571cf7f735c5072796 | |
| parent | 0c5fc92622ed5531ff324b20f014e9e3092f0187 (diff) | |
| download | lwn-4466d6d2f80c1193e0845d110277c56da77a6418.tar.gz lwn-4466d6d2f80c1193e0845d110277c56da77a6418.zip | |
tty: fix crash in release_tty if tty->port is not set
Commit 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing
tty_port") didn't fully prevent the crash as the cleanup path in
tty_init_dev() calls release_tty() which dereferences tty->port
without checking it for non-null.
Add tty->port checks to release_tty to avoid the kernel crash.
Fixes: 2ae0b31e0face ("tty: don't crash in tty_init_dev when missing tty_port")
Signed-off-by: Matthias Reichl <hias@horus.com>
Link: https://lore.kernel.org/r/20201105123432.4448-1-hias@horus.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 7a4c02548fb3..9f8b9a567b35 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1515,10 +1515,12 @@ static void release_tty(struct tty_struct *tty, int idx) tty->ops->shutdown(tty); tty_save_termios(tty); tty_driver_remove_tty(tty->driver, tty); - tty->port->itty = NULL; + if (tty->port) + tty->port->itty = NULL; if (tty->link) tty->link->port->itty = NULL; - tty_buffer_cancel_work(tty->port); + if (tty->port) + tty_buffer_cancel_work(tty->port); if (tty->link) tty_buffer_cancel_work(tty->link->port); |