linux/include/uapi/linux/auto_dev-ioctl.h
Arnd Bergmann e910c8e3aa autofs: use flexible array in ioctl structure
Commit df8fc4e934 ("kbuild: Enable -fstrict-flex-arrays=3") introduced a warning
for the autofs_dev_ioctl structure:

In function 'check_name',
    inlined from 'validate_dev_ioctl' at fs/autofs/dev-ioctl.c:131:9,
    inlined from '_autofs_dev_ioctl' at fs/autofs/dev-ioctl.c:624:8:
fs/autofs/dev-ioctl.c:33:14: error: 'strchr' reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread]
   33 |         if (!strchr(name, '/'))
      |              ^~~~~~~~~~~~~~~~~
In file included from include/linux/auto_dev-ioctl.h:10,
                 from fs/autofs/autofs_i.h:10,
                 from fs/autofs/dev-ioctl.c:14:
include/uapi/linux/auto_dev-ioctl.h: In function '_autofs_dev_ioctl':
include/uapi/linux/auto_dev-ioctl.h:112:14: note: source object 'path' of size 0
  112 |         char path[0];
      |              ^~~~

This is easily fixed by changing the gnu 0-length array into a c99
flexible array. Since this is a uapi structure, we have to be careful
about possible regressions but this one should be fine as they are
equivalent here. While it would break building with ancient gcc versions
that predate c99, it helps building with --std=c99 and -Wpedantic builds
in user space, as well as non-gnu compilers. This means we probably
also want it fixed in stable kernels.

Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: Gustavo A. R. Silva" <gustavoars@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230523081944.581710-1-arnd@kernel.org
2023-05-30 16:42:00 -07:00

217 lines
4.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
* Copyright 2008 Red Hat, Inc. All rights reserved.
* Copyright 2008 Ian Kent <raven@themaw.net>
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*/
#ifndef _UAPI_LINUX_AUTO_DEV_IOCTL_H
#define _UAPI_LINUX_AUTO_DEV_IOCTL_H
#include <linux/auto_fs.h>
#include <linux/string.h>
#define AUTOFS_DEVICE_NAME "autofs"
#define AUTOFS_DEV_IOCTL_VERSION_MAJOR 1
#define AUTOFS_DEV_IOCTL_VERSION_MINOR 1
#define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl)
/*
* An ioctl interface for autofs mount point control.
*/
struct args_protover {
__u32 version;
};
struct args_protosubver {
__u32 sub_version;
};
struct args_openmount {
__u32 devid;
};
struct args_ready {
__u32 token;
};
struct args_fail {
__u32 token;
__s32 status;
};
struct args_setpipefd {
__s32 pipefd;
};
struct args_timeout {
__u64 timeout;
};
struct args_requester {
__u32 uid;
__u32 gid;
};
struct args_expire {
__u32 how;
};
struct args_askumount {
__u32 may_umount;
};
struct args_ismountpoint {
union {
struct args_in {
__u32 type;
} in;
struct args_out {
__u32 devid;
__u32 magic;
} out;
};
};
/*
* All the ioctls use this structure.
* When sending a path size must account for the total length
* of the chunk of memory otherwise it is the size of the
* structure.
*/
struct autofs_dev_ioctl {
__u32 ver_major;
__u32 ver_minor;
__u32 size; /* total size of data passed in
* including this struct */
__s32 ioctlfd; /* automount command fd */
/* Command parameters */
union {
struct args_protover protover;
struct args_protosubver protosubver;
struct args_openmount openmount;
struct args_ready ready;
struct args_fail fail;
struct args_setpipefd setpipefd;
struct args_timeout timeout;
struct args_requester requester;
struct args_expire expire;
struct args_askumount askumount;
struct args_ismountpoint ismountpoint;
};
char path[];
};
static inline void init_autofs_dev_ioctl(struct autofs_dev_ioctl *in)
{
memset(in, 0, AUTOFS_DEV_IOCTL_SIZE);
in->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
in->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
in->size = AUTOFS_DEV_IOCTL_SIZE;
in->ioctlfd = -1;
}
enum {
/* Get various version info */
AUTOFS_DEV_IOCTL_VERSION_CMD = 0x71,
AUTOFS_DEV_IOCTL_PROTOVER_CMD,
AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD,
/* Open mount ioctl fd */
AUTOFS_DEV_IOCTL_OPENMOUNT_CMD,
/* Close mount ioctl fd */
AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD,
/* Mount/expire status returns */
AUTOFS_DEV_IOCTL_READY_CMD,
AUTOFS_DEV_IOCTL_FAIL_CMD,
/* Activate/deactivate autofs mount */
AUTOFS_DEV_IOCTL_SETPIPEFD_CMD,
AUTOFS_DEV_IOCTL_CATATONIC_CMD,
/* Expiry timeout */
AUTOFS_DEV_IOCTL_TIMEOUT_CMD,
/* Get mount last requesting uid and gid */
AUTOFS_DEV_IOCTL_REQUESTER_CMD,
/* Check for eligible expire candidates */
AUTOFS_DEV_IOCTL_EXPIRE_CMD,
/* Request busy status */
AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD,
/* Check if path is a mountpoint */
AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD,
};
#define AUTOFS_DEV_IOCTL_VERSION \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_VERSION_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_PROTOVER \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_PROTOVER_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_PROTOSUBVER \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_OPENMOUNT \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_OPENMOUNT_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_CLOSEMOUNT \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_READY \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_READY_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_FAIL \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_FAIL_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_SETPIPEFD \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_SETPIPEFD_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_CATATONIC \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_CATATONIC_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_TIMEOUT \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_TIMEOUT_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_REQUESTER \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_REQUESTER_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_EXPIRE \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_EXPIRE_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_ASKUMOUNT \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD, struct autofs_dev_ioctl)
#define AUTOFS_DEV_IOCTL_ISMOUNTPOINT \
_IOWR(AUTOFS_IOCTL, \
AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD, struct autofs_dev_ioctl)
#endif /* _UAPI_LINUX_AUTO_DEV_IOCTL_H */