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author | Chengguang Xu <cgxu519@gmx.com> | 2019-02-15 20:27:11 +0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 06:46:27 -0700 |
commit | 65ec64f28a882096d9976963e2ccefd85085fb1a (patch) | |
tree | a2ee29fc4a812999206f1a209e7a90d36d7053ca | |
parent | fc242af86d0713d7a1edd7b757d92fb03b3047e0 (diff) | |
download | linux-rpi3-65ec64f28a882096d9976963e2ccefd85085fb1a.tar.gz linux-rpi3-65ec64f28a882096d9976963e2ccefd85085fb1a.tar.bz2 linux-rpi3-65ec64f28a882096d9976963e2ccefd85085fb1a.zip |
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>
-rw-r--r-- | fs/char_dev.c | 6 |
1 files changed, 6 insertions, 0 deletions
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; |