Commit 9b48a687 authored Aug 02, 2018 by Dan Carpenter Committed by Greg Kroah-Hartman Sep 26, 2018

uio: potential double frees if __uio_register_device() fails



[ Upstream commit f019f07ecf6a6b8bd6d7853bce70925d90af02d1 ]

The uio_unregister_device() function assumes that if "info->uio_dev" is
non-NULL that means "info" is fully allocated.  Setting info->uio_de
has to be the last thing in the function.

In the current code, if request_threaded_irq() fails then we return with
info->uio_dev set to non-NULL but info is not fully allocated and it can
lead to double frees.

Fixes: beafc54c ("UIO: Add the User IO core code")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f2675e34

drivers/uio/uio.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -832,8 +832,6 @@ int __uio_register_device(struct module *owner,
		if (ret)
		goto err_uio_dev_add_attributes;

		info->uio_dev = idev;

		if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
		ret = devm_request_irq(idev->dev, info->irq, uio_interrupt,
		info->irq_flags, info->name, idev);
		@@ -841,6 +839,7 @@ int __uio_register_device(struct module *owner,
		goto err_request_irq;
		}

		info->uio_dev = idev;
		return 0;

		err_request_irq: