From de36e16d1557a0b6eb328bc3516359a12ba5c25c Mon Sep 17 00:00:00 2001
From: Chengguang Xu <cgxu519@gmx.com>
Date: Fri, 15 Feb 2019 20:27:11 +0800
Subject: [PATCH] chardev: add additional check for minor range overlap
Git-commit: de36e16d1557a0b6eb328bc3516359a12ba5c25c
Patch-mainline: v5.2-rc1
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
fs/char_dev.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/char_dev.c b/fs/char_dev.c
index a279c58fe360..8a63cfa29005 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -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;
--
2.16.4