Commit f019f07e authored Aug 02, 2018 by Dan Carpenter Committed by Greg Kroah-Hartman Aug 02, 2018

uio: potential double frees if __uio_register_device() fails



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>

parent c01513b4

drivers/uio/uio.c

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -953,8 +953,6 @@ int __uio_register_device(struct module *owner,
	if (ret)		if (ret)
	goto err_uio_dev_add_attributes;		goto err_uio_dev_add_attributes;

	info->uio_dev = idev;

	if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {		if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
	/*		/*
	* Note that we deliberately don't use devm_request_irq		* Note that we deliberately don't use devm_request_irq
	@@ -971,6 +969,7 @@ int __uio_register_device(struct module *owner,
	goto err_request_irq;		goto err_request_irq;
	}		}

			info->uio_dev = idev;
	return 0;		return 0;

	err_request_irq:		err_request_irq: