Commit 4712d379 authored Feb 15, 2019 by Chengguang Xu Committed by Greg Kroah-Hartman Apr 02, 2019

chardev: add a check for given minor range



register_chrdev_region() carefully checks minor range
before calling __register_chrdev_region() but there is
another path from alloc_chrdev_region() which does not
check the range properly. So add a check for given minor
range in __register_chrdev_region().

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent de36e16d

fs/char_dev.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -104,6 +104,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
		int ret = 0;
		int i;

		if (minorct > MINORMASK + 1 - baseminor) {
		pr_err("CHRDEV \"%s\" minor range requested (%u-%u) is out of range of maximum range (%u-%u) for a single major\n",
		name, baseminor, baseminor + minorct - 1, 0, MINORMASK);
		return ERR_PTR(-EINVAL);
		}

		cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL);
		if (cd == NULL)
		return ERR_PTR(-ENOMEM);

Admin message