Messages in this thread Patch in this message | | | From | Chengguang Xu <> | Subject | [PATCH v3 2/4] chardev: add a check for given minor range | Date | Fri, 5 Apr 2019 19:27:09 +0800 |
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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
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