autofs: fix dev ioctl number range check

The count of miscellaneous device ioctls in fs/autofs4/autofs_i.h is wrong.

The number of ioctls is the difference between AUTOFS_DEV_IOCTL_VERSION_CMD
and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD (14) not the difference between
AUTOFS_IOC_COUNT and 11 (21).

[kusumi.tomohiro@gmail.com: fix typo that made the count macro negative]
 Link: http://lkml.kernel.org/r/20160831033420.9910.16809.stgit@pluto.themaw.net
Link: http://lkml.kernel.org/r/20160812024841.12352.11975.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Tomohiro Kusumi <kusumi.tomohiro@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ian Kent 2016-10-11 13:53:02 -07:00 committed by Linus Torvalds
parent b6e3795a06
commit aa8419367b
2 changed files with 3 additions and 2 deletions

View File

@ -20,7 +20,8 @@
#define AUTOFS_IOC_COUNT 32
#define AUTOFS_DEV_IOCTL_IOC_FIRST (AUTOFS_DEV_IOCTL_VERSION)
#define AUTOFS_DEV_IOCTL_IOC_COUNT (AUTOFS_IOC_COUNT - 11)
#define AUTOFS_DEV_IOCTL_IOC_COUNT \
(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
#include <linux/kernel.h>
#include <linux/slab.h>

View File

@ -642,7 +642,7 @@ static int _autofs_dev_ioctl(unsigned int command,
cmd = _IOC_NR(command);
if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) {
cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
return -ENOTTY;
}