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| author |   Chengguang Xu <cgxu519@gmx.com> | 2019-02-15 20:27:12 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-02 17:49:58 +0200 |
| commit | 4712d3796f19b32241b41e538107fb7ae7a3fcff (patch) | |
| tree | 662545733a34a647a2c884312617c8cb0c48168e /fs/char_dev.c | |
| parent | chardev: add additional check for minor range overlap (diff) | |
| download | linux-dev-4712d3796f19b32241b41e538107fb7ae7a3fcff.tar.xz linux-dev-4712d3796f19b32241b41e538107fb7ae7a3fcff.zip | |
chardev: add a check for given minor range
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/char_dev.c')
| -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 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); |