From: Chengguang Xu <cgxu519@gmx.com>
To: gregkh@linuxfoundation.org
Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
Chengguang Xu <cgxu519@gmx.com>
Subject: [PATCH v2 2/4] chardev: add a check for given minor range
Date: Fri, 15 Feb 2019 20:27:12 +0800 [thread overview]
Message-ID: <20190215122714.28842-2-cgxu519@gmx.com> (raw)
In-Reply-To: <20190215122714.28842-1-cgxu519@gmx.com>
register_chrdev_region() carefully checks minor range
before calling __register_chrdev_region() but there is
another path from alloc_chrdev_region() which does not
check the range properly. So add a check for given minor
range in __register_chrdev_region().
Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
---
v1->v2:
- Split fix and cleanup patches.
- Remove printing minor range in chrdev_show().
fs/char_dev.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 8a63cfa29005..6803e98414f1 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -104,6 +104,12 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
int ret = 0;
int i;
+ if (minorct > MINORMASK + 1 - baseminor) {
+ pr_err("CHRDEV \"%s\" minor range requested (%u-%u) is out of range of maximum range (%u-%u) for a single major\n",
+ name, baseminor, baseminor + minorct - 1, 0, MINORMASK);
+ return ERR_PTR(-EINVAL);
+ }
+
cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL);
if (cd == NULL)
return ERR_PTR(-ENOMEM);
--
2.20.1
next prev parent reply other threads:[~2019-02-15 12:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 12:27 [PATCH v2 1/4] chardev: add additional check for minor range overlap Chengguang Xu
2019-02-15 12:27 ` Chengguang Xu [this message]
2019-02-15 12:27 ` [PATCH v2 3/4] chardev: code cleanup for __register_chrdev_region() Chengguang Xu
2019-02-15 12:27 ` [PATCH v2 4/4] chardev: update comment based on the code Chengguang Xu
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