From de36e16d1557a0b6eb328bc3516359a12ba5c25c Mon Sep 17 00:00:00 2001 From: Chengguang Xu Date: Fri, 15 Feb 2019 20:27:11 +0800 Subject: chardev: add additional check for minor range overlap Current overlap checking cannot correctly handle a case which is baseminor < existing baseminor && baseminor + minorct > existing baseminor + minorct. Signed-off-by: Chengguang Xu Signed-off-by: Greg Kroah-Hartman --- 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; -- cgit v1.2.3