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Commit | Line | Data |
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1143c684 SL |
1 | From 08c271e02d02ab497ace99b9f4fa7486836500a0 Mon Sep 17 00:00:00 2001 |
2 | From: Chengguang Xu <cgxu519@gmx.com> | |
3 | Date: Fri, 15 Feb 2019 20:27:11 +0800 | |
4 | Subject: chardev: add additional check for minor range overlap | |
5 | ||
6 | [ Upstream commit de36e16d1557a0b6eb328bc3516359a12ba5c25c ] | |
7 | ||
8 | Current overlap checking cannot correctly handle | |
9 | a case which is baseminor < existing baseminor && | |
10 | baseminor + minorct > existing baseminor + minorct. | |
11 | ||
12 | Signed-off-by: Chengguang Xu <cgxu519@gmx.com> | |
13 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
14 | Signed-off-by: Sasha Levin <sashal@kernel.org> | |
15 | --- | |
16 | fs/char_dev.c | 6 ++++++ | |
17 | 1 file changed, 6 insertions(+) | |
18 | ||
19 | diff --git a/fs/char_dev.c b/fs/char_dev.c | |
20 | index 24b142569ca9b..d0655ca894816 100644 | |
21 | --- a/fs/char_dev.c | |
22 | +++ b/fs/char_dev.c | |
23 | @@ -130,6 +130,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, | |
24 | ret = -EBUSY; | |
25 | goto out; | |
26 | } | |
27 | + | |
28 | + if (new_min < old_min && new_max > old_max) { | |
29 | + ret = -EBUSY; | |
30 | + goto out; | |
31 | + } | |
32 | + | |
33 | } | |
34 | ||
35 | cd->next = *cp; | |
36 | -- | |
37 | 2.20.1 | |
38 |