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kernel-ark/fs/ext3/ioctl.c
Duane Griffin 04143e2fb9 ext3: 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 08:31:01 -08:00

350 lines
8.1 KiB
C
Raw Blame History

/*
* linux/fs/ext3/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 <linux/fs.h>
#include <linux/jbd.h>
#include <linux/capability.h>
#include <linux/ext3_fs.h>
#include <linux/ext3_jbd.h>
#include <linux/mount.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
unsigned long arg)
{
struct ext3_inode_info *ei = EXT3_I(inode);
unsigned int flags;
unsigned short rsv_window_size;
ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
switch (cmd) {
case EXT3_IOC_GETFLAGS:
ext3_get_inode_flags(ei);
flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
return put_user(flags, (int __user *) arg);
case EXT3_IOC_SETFLAGS: {
handle_t *handle = NULL;
int err;
struct ext3_iloc iloc;
unsigned int oldflags;
unsigned int jflag;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!is_owner_or_cap(inode)) {
err = -EACCES;
goto flags_out;
}
if (get_user(flags, (int __user *) arg)) {
err = -EFAULT;
goto flags_out;
}
flags = ext3_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);
err = -EPERM;
goto flags_out;
}
oldflags = ei->i_flags;
/* The JOURNAL_DATA flag is modifiable only by root */
jflag = flags & EXT3_JOURNAL_DATA_FL;
/*
* 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) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
err = -EPERM;
goto flags_out;
}
}
/*
* The JOURNAL_DATA flag can only be changed by
* the relevant capability.
*/
if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
if (!capable(CAP_SYS_RESOURCE)) {
mutex_unlock(&inode->i_mutex);
err = -EPERM;
goto flags_out;
}
}
handle = ext3_journal_start(inode, 1);
if (IS_ERR(handle)) {
mutex_unlock(&inode->i_mutex);
err = PTR_ERR(handle);
goto flags_out;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
err = ext3_reserve_inode_write(handle, inode, &iloc);
if (err)
goto flags_err;
flags = flags & EXT3_FL_USER_MODIFIABLE;
flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
ei->i_flags = flags;
ext3_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
ext3_journal_stop(handle);
if (err) {
mutex_unlock(&inode->i_mutex);
return err;
}
if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
err = ext3_change_inode_journal_flag(inode, jflag);
mutex_unlock(&inode->i_mutex);
flags_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT3_IOC_GETVERSION:
case EXT3_IOC_GETVERSION_OLD:
return put_user(inode->i_generation, (int __user *) arg);
case EXT3_IOC_SETVERSION:
case EXT3_IOC_SETVERSION_OLD: {
handle_t *handle;
struct ext3_iloc iloc;
__u32 generation;
int err;
if (!is_owner_or_cap(inode))
return -EPERM;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (get_user(generation, (int __user *) arg)) {
err = -EFAULT;
goto setversion_out;
}
handle = ext3_journal_start(inode, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto setversion_out;
}
err = ext3_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
inode->i_ctime = CURRENT_TIME_SEC;
inode->i_generation = generation;
err = ext3_mark_iloc_dirty(handle, inode, &iloc);
}
ext3_journal_stop(handle);
setversion_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
#ifdef CONFIG_JBD_DEBUG
case EXT3_IOC_WAIT_FOR_READONLY:
/*
* This is racy - by the time we're woken up and running,
* the superblock could be released. And the module could
* have been unloaded. So sue me.
*
* Returns 1 if it slept, else zero.
*/
{
struct super_block *sb = inode->i_sb;
DECLARE_WAITQUEUE(wait, current);
int ret = 0;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
schedule();
ret = 1;
}
remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
return ret;
}
#endif
case EXT3_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 EXT3_IOC_SETRSVSZ: {
int err;
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!is_owner_or_cap(inode)) {
err = -EACCES;
goto setrsvsz_out;
}
if (get_user(rsv_window_size, (int __user *)arg)) {
err = -EFAULT;
goto setrsvsz_out;
}
if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
/*
* need to allocate reservation structure for this inode
* before set the window size
*/
mutex_lock(&ei->truncate_mutex);
if (!ei->i_block_alloc_info)
ext3_init_block_alloc_info(inode);
if (ei->i_block_alloc_info){
struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
setrsvsz_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT3_IOC_GROUP_EXTEND: {
ext3_fsblk_t n_blocks_count;
struct super_block *sb = inode->i_sb;
int err, err2;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (get_user(n_blocks_count, (__u32 __user *)arg)) {
err = -EFAULT;
goto group_extend_out;
}
err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
journal_lock_updates(EXT3_SB(sb)->s_journal);
err2 = journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
if (err == 0)
err = err2;
group_extend_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT3_IOC_GROUP_ADD: {
struct ext3_new_group_data input;
struct super_block *sb = inode->i_sb;
int err, err2;
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
sizeof(input))) {
err = -EFAULT;
goto group_add_out;
}
err = ext3_group_add(sb, &input);
journal_lock_updates(EXT3_SB(sb)->s_journal);
err2 = journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
if (err == 0)
err = err2;
group_add_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long ext3_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
int ret;
/* These are just misnamed, they actually get/put from/to user an int */
switch (cmd) {
case EXT3_IOC32_GETFLAGS:
cmd = EXT3_IOC_GETFLAGS;
break;
case EXT3_IOC32_SETFLAGS:
cmd = EXT3_IOC_SETFLAGS;
break;
case EXT3_IOC32_GETVERSION:
cmd = EXT3_IOC_GETVERSION;
break;
case EXT3_IOC32_SETVERSION:
cmd = EXT3_IOC_SETVERSION;
break;
case EXT3_IOC32_GROUP_EXTEND:
cmd = EXT3_IOC_GROUP_EXTEND;
break;
case EXT3_IOC32_GETVERSION_OLD:
cmd = EXT3_IOC_GETVERSION_OLD;
break;
case EXT3_IOC32_SETVERSION_OLD:
cmd = EXT3_IOC_SETVERSION_OLD;
break;
#ifdef CONFIG_JBD_DEBUG
case EXT3_IOC32_WAIT_FOR_READONLY:
cmd = EXT3_IOC_WAIT_FOR_READONLY;
break;
#endif
case EXT3_IOC32_GETRSVSZ:
cmd = EXT3_IOC_GETRSVSZ;
break;
case EXT3_IOC32_SETRSVSZ:
cmd = EXT3_IOC_SETRSVSZ;
break;
case EXT3_IOC_GROUP_ADD:
break;
default:
return -ENOIOCTLCMD;
}
lock_kernel();
ret = ext3_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
unlock_kernel();
return ret;
}
#endif
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