diff options
| author | Leon Yu <chianglungyu@gmail.com> | 2015-09-07 13:08:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-04 18:51:42 +0100 |
| commit | c1a752ba2d6b8a52879c7ab637cff38359ea9827 (patch) | |
| tree | 97a4090ddc27d70b3ca2c4b50941748395621a0e | |
| parent | 0c727a42043f79db210cdde0366f9137b9c6bf5a (diff) | |
| download | linux-c1a752ba2d6b8a52879c7ab637cff38359ea9827.tar.bz2 | |
tty: don't leak cdev in tty_cdev_add()
Commit a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly
dynamic") which mixes using cdev_alloc() and cdev_init() is problematic.
Subsequent call to cdev_init() after cdev_alloc() sets kobj release method
from cdev_dynamic_release() to cdev_default_release() and thus makes it
impossible to free allocated cdev.
This patch also consolidates error path of cdev_add() as cdev can also leak
here if things went wrong.
Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Fixes: a3a10ce3429e ("Avoid usb reset crashes by making tty_io cdevs truly dynamic")
Acked-by: Richard Watts <rrw@kynesim.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/tty_io.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 02785d844354..17b027242734 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -3151,13 +3151,18 @@ struct class *tty_class; static int tty_cdev_add(struct tty_driver *driver, dev_t dev, unsigned int index, unsigned int count) { + int err; + /* init here, since reused cdevs cause crashes */ driver->cdevs[index] = cdev_alloc(); if (!driver->cdevs[index]) return -ENOMEM; - cdev_init(driver->cdevs[index], &tty_fops); + driver->cdevs[index]->ops = &tty_fops; driver->cdevs[index]->owner = driver->owner; - return cdev_add(driver->cdevs[index], dev, count); + err = cdev_add(driver->cdevs[index], dev, count); + if (err) + kobject_put(&driver->cdevs[index]->kobj); + return err; } /** |