android_kernel_xiaomi_sm8350/fs/ext2/ioctl.c
Duane Griffin ef8b646183 ext2: tighten restrictions on inode flags
At the moment there are few restrictions on which flags may be set on
which inodes.  Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links.  Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.

Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:00 -08:00

180 lines
4.3 KiB
C

/*
* linux/fs/ext2/ioctl.c
*
* Copyright (C) 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*/
#include "ext2.h"
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/smp_lock.h>
#include <asm/current.h>
#include <asm/uaccess.h>
long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = filp->f_dentry->d_inode;
struct ext2_inode_info *ei = EXT2_I(inode);
unsigned int flags;
unsigned short rsv_window_size;
int ret;
ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
switch (cmd) {
case EXT2_IOC_GETFLAGS:
ext2_get_inode_flags(ei);
flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
return put_user(flags, (int __user *) arg);
case EXT2_IOC_SETFLAGS: {
unsigned int oldflags;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (!is_owner_or_cap(inode)) {
ret = -EACCES;
goto setflags_out;
}
if (get_user(flags, (int __user *) arg)) {
ret = -EFAULT;
goto setflags_out;
}
flags = ext2_mask_flags(inode->i_mode, flags);
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
oldflags = ei->i_flags;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
}
flags = flags & EXT2_FL_USER_MODIFIABLE;
flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
ei->i_flags = flags;
mutex_unlock(&inode->i_mutex);
ext2_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
setflags_out:
mnt_drop_write(filp->f_path.mnt);
return ret;
}
case EXT2_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *) arg);
case EXT2_IOC_SETVERSION:
if (!is_owner_or_cap(inode))
return -EPERM;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (get_user(inode->i_generation, (int __user *) arg)) {
ret = -EFAULT;
} else {
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
}
mnt_drop_write(filp->f_path.mnt);
return ret;
case EXT2_IOC_GETRSVSZ:
if (test_opt(inode->i_sb, RESERVATION)
&& S_ISREG(inode->i_mode)
&& ei->i_block_alloc_info) {
rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
return put_user(rsv_window_size, (int __user *)arg);
}
return -ENOTTY;
case EXT2_IOC_SETRSVSZ: {
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(rsv_window_size, (int __user *)arg))
return -EFAULT;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
/*
* need to allocate reservation structure for this inode
* before set the window size
*/
/*
* XXX What lock should protect the rsv_goal_size?
* Accessed in ext2_get_block only. ext3 uses i_truncate.
*/
mutex_lock(&ei->truncate_mutex);
if (!ei->i_block_alloc_info)
ext2_init_block_alloc_info(inode);
if (ei->i_block_alloc_info){
struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
mnt_drop_write(filp->f_path.mnt);
return 0;
}
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
/* These are just misnamed, they actually get/put from/to user an int */
switch (cmd) {
case EXT2_IOC32_GETFLAGS:
cmd = EXT2_IOC_GETFLAGS;
break;
case EXT2_IOC32_SETFLAGS:
cmd = EXT2_IOC_SETFLAGS;
break;
case EXT2_IOC32_GETVERSION:
cmd = EXT2_IOC_GETVERSION;
break;
case EXT2_IOC32_SETVERSION:
cmd = EXT2_IOC_SETVERSION;
break;
default:
return -ENOIOCTLCMD;
}
return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif