Commit 65ec64f2 authored Feb 15, 2019 by Chengguang Xu Committed by Greg Kroah-Hartman May 31, 2019

chardev: add additional check for minor range overlap



[ Upstream commit de36e16d1557a0b6eb328bc3516359a12ba5c25c ]

Current overlap checking cannot correctly handle
a case which is baseminor < existing baseminor &&
baseminor + minorct > existing baseminor + minorct.

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

parent fc242af8

fs/char_dev.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -159,6 +159,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
		ret = -EBUSY;
		goto out;
		}

		if (new_min < old_min && new_max > old_max) {
		ret = -EBUSY;
		goto out;
		}

		}

		cd->next = *cp;