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authorLeon Yu <chianglungyu@gmail.com>2015-09-07 13:08:37 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-04 18:51:42 +0100
commitc1a752ba2d6b8a52879c7ab637cff38359ea9827 (patch)
tree97a4090ddc27d70b3ca2c4b50941748395621a0e
parent0c727a42043f79db210cdde0366f9137b9c6bf5a (diff)
downloadop-kernel-dev-c1a752ba2d6b8a52879c7ab637cff38359ea9827.zip
op-kernel-dev-c1a752ba2d6b8a52879c7ab637cff38359ea9827.tar.gz
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.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 02785d8..17b0272 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;
}
/**
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