From: Jiri Slaby <jslaby@suse.cz> mainline inclusion from mainline-v5.5-rc1 commit 2ae0b31e0faced43c011ce3221f2535721cb6a66 category: bugfix bugzilla: 82118 CVE: N/A -------------------------------- We currently warn the user when tty->port is not set in tty_init_dev yet. The warning says that the kernel will crash later. And it really will only few lines below at: tty->port->itty = tty; So be nice and avoid the crash -- return an error instead. And update the warning. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lore.kernel.org/r/20191122101721.7222-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yi Yang <yiyang13@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Laibin Qiu <qiulaibin@huawei.com> --- drivers/tty/tty_io.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 3025c39ba6b1..dc522e994e80 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1343,9 +1343,12 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) if (!tty->port) tty->port = driver->ports[idx]; - WARN_RATELIMIT(!tty->port, - "%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n", - __func__, tty->driver->name); + if (WARN_RATELIMIT(!tty->port, + "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", + __func__, tty->driver->name)) { + retval = -EINVAL; + goto err_release_lock; + } retval = tty_ldisc_lock(tty, 5 * HZ); if (retval) -- 2.22.0