Commit 42a74f20 authored by Dave Hansen's avatar Dave Hansen Committed by Al Viro

[PATCH] r/o bind mounts: elevate write count for ioctls()

Some ioctl()s can cause writes to the filesystem.  Take these, and make them
use mnt_want/drop_write() instead.

[AV: updated]
Acked-by: default avatarAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDave Hansen <haveblue@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 20ddee2c
......@@ -12,6 +12,7 @@
#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>
......@@ -23,6 +24,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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);
......@@ -34,14 +36,19 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case EXT2_IOC_SETFLAGS: {
unsigned int oldflags;
if (IS_RDONLY(inode))
return -EROFS;
ret = mnt_want_write(filp->f_path.mnt);
if (ret)
return ret;
if (!is_owner_or_cap(inode))
return -EACCES;
if (!is_owner_or_cap(inode)) {
ret = -EACCES;
goto setflags_out;
}
if (get_user(flags, (int __user *) arg))
return -EFAULT;
if (get_user(flags, (int __user *) arg)) {
ret = -EFAULT;
goto setflags_out;
}
if (!S_ISDIR(inode->i_mode))
flags &= ~EXT2_DIRSYNC_FL;
......@@ -50,7 +57,8 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
ret = -EPERM;
goto setflags_out;
}
oldflags = ei->i_flags;
......@@ -63,7 +71,8 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
ret = -EPERM;
goto setflags_out;
}
}
......@@ -75,20 +84,26 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
ext2_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
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;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(inode->i_generation, (int __user *) arg))
return -EFAULT;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
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)
......@@ -102,15 +117,16 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (IS_RDONLY(inode))
return -EROFS;
if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
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;
......@@ -131,6 +147,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
mnt_drop_write(filp->f_path.mnt);
return 0;
}
default:
......
......@@ -12,6 +12,7 @@
#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>
......@@ -38,14 +39,19 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
unsigned int oldflags;
unsigned int jflag;
if (IS_RDONLY(inode))
return -EROFS;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!is_owner_or_cap(inode))
return -EACCES;
if (!is_owner_or_cap(inode)) {
err = -EACCES;
goto flags_out;
}
if (get_user(flags, (int __user *) arg))
return -EFAULT;
if (get_user(flags, (int __user *) arg)) {
err = -EFAULT;
goto flags_out;
}
if (!S_ISDIR(inode->i_mode))
flags &= ~EXT3_DIRSYNC_FL;
......@@ -54,7 +60,8 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
err = -EPERM;
goto flags_out;
}
oldflags = ei->i_flags;
......@@ -70,7 +77,8 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
err = -EPERM;
goto flags_out;
}
}
......@@ -81,7 +89,8 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
if (!capable(CAP_SYS_RESOURCE)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
err = -EPERM;
goto flags_out;
}
}
......@@ -89,7 +98,8 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
handle = ext3_journal_start(inode, 1);
if (IS_ERR(handle)) {
mutex_unlock(&inode->i_mutex);
return PTR_ERR(handle);
err = PTR_ERR(handle);
goto flags_out;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
......@@ -115,6 +125,8 @@ flags_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:
......@@ -129,14 +141,18 @@ flags_err:
if (!is_owner_or_cap(inode))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(generation, (int __user *) arg))
return -EFAULT;
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))
return PTR_ERR(handle);
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;
......@@ -144,6 +160,8 @@ flags_err:
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
......@@ -179,18 +197,24 @@ flags_err:
}
return -ENOTTY;
case EXT3_IOC_SETRSVSZ: {
int err;
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (IS_RDONLY(inode))
return -EROFS;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!is_owner_or_cap(inode))
return -EACCES;
if (!is_owner_or_cap(inode)) {
err = -EACCES;
goto setrsvsz_out;
}
if (get_user(rsv_window_size, (int __user *)arg))
return -EFAULT;
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;
......@@ -208,7 +232,9 @@ flags_err:
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
return 0;
setrsvsz_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT3_IOC_GROUP_EXTEND: {
ext3_fsblk_t n_blocks_count;
......@@ -218,17 +244,20 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(n_blocks_count, (__u32 __user *)arg))
return -EFAULT;
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);
journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
group_extend_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT3_IOC_GROUP_ADD: {
......@@ -239,18 +268,22 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
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)))
return -EFAULT;
sizeof(input))) {
err = -EFAULT;
goto group_add_out;
}
err = ext3_group_add(sb, &input);
journal_lock_updates(EXT3_SB(sb)->s_journal);
journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
group_add_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
......
......@@ -15,6 +15,7 @@
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
#include <asm/uaccess.h>
int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
......@@ -38,24 +39,25 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
unsigned int oldflags;
unsigned int jflag;
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(flags, (int __user *) arg))
return -EFAULT;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!S_ISDIR(inode->i_mode))
flags &= ~EXT4_DIRSYNC_FL;
err = -EPERM;
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);
return -EPERM;
}
if (IS_NOQUOTA(inode))
goto flags_out;
oldflags = ei->i_flags;
/* The JOURNAL_DATA flag is modifiable only by root */
......@@ -68,10 +70,8 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
}
if (!capable(CAP_LINUX_IMMUTABLE))
goto flags_out;
}
/*
......@@ -79,17 +79,14 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
* the relevant capability.
*/
if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
if (!capable(CAP_SYS_RESOURCE)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
}
if (!capable(CAP_SYS_RESOURCE))
goto flags_out;
}
handle = ext4_journal_start(inode, 1);
if (IS_ERR(handle)) {
mutex_unlock(&inode->i_mutex);
return PTR_ERR(handle);
err = PTR_ERR(handle);
goto flags_out;
}
if (IS_SYNC(inode))
handle->h_sync = 1;
......@@ -107,14 +104,14 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
ext4_journal_stop(handle);
if (err) {
mutex_unlock(&inode->i_mutex);
return err;
}
if (err)
goto flags_out;
if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
err = ext4_change_inode_journal_flag(inode, jflag);
flags_out:
mutex_unlock(&inode->i_mutex);
mnt_drop_write(filp->f_path.mnt);
return err;
}
case EXT4_IOC_GETVERSION:
......@@ -129,14 +126,20 @@ flags_err:
if (!is_owner_or_cap(inode))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(generation, (int __user *) arg))
return -EFAULT;
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 = ext4_journal_start(inode, 1);
if (IS_ERR(handle))
return PTR_ERR(handle);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto setversion_out;
}
err = ext4_reserve_inode_write(handle, inode, &iloc);
if (err == 0) {
inode->i_ctime = ext4_current_time(inode);
......@@ -144,6 +147,8 @@ flags_err:
err = ext4_mark_iloc_dirty(handle, inode, &iloc);
}
ext4_journal_stop(handle);
setversion_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
#ifdef CONFIG_JBD2_DEBUG
......@@ -179,19 +184,21 @@ flags_err:
}
return -ENOTTY;
case EXT4_IOC_SETRSVSZ: {
int err;
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(rsv_window_size, (int __user *)arg))
return -EFAULT;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
......@@ -208,6 +215,7 @@ flags_err:
rsv->rsv_goal_size = rsv_window_size;
}
up_write(&ei->i_data_sem);
mnt_drop_write(filp->f_path.mnt);
return 0;
}
case EXT4_IOC_GROUP_EXTEND: {
......@@ -218,16 +226,18 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (get_user(n_blocks_count, (__u32 __user *)arg))
return -EFAULT;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
jbd2_journal_flush(EXT4_SB(sb)->s_journal);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
mnt_drop_write(filp->f_path.mnt);
return err;
}
......@@ -239,17 +249,19 @@ flags_err:
if (!capable(CAP_SYS_RESOURCE))
return -EPERM;
if (IS_RDONLY(inode))
return -EROFS;
if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
sizeof(input)))
return -EFAULT;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
err = ext4_group_add(sb, &input);
jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
jbd2_journal_flush(EXT4_SB(sb)->s_journal);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
mnt_drop_write(filp->f_path.mnt);
return err;
}
......
......@@ -8,6 +8,7 @@
#include <linux/capability.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/smp_lock.h>
......@@ -46,10 +47,9 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
mutex_lock(&inode->i_mutex);
if (IS_RDONLY(inode)) {
err = -EROFS;
goto up;
}
err = mnt_want_write(filp->f_path.mnt);
if (err)
goto up_no_drop_write;
/*
* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
......@@ -105,7 +105,9 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
mark_inode_dirty(inode);
up:
up:
mnt_drop_write(filp->f_path.mnt);
up_no_drop_write:
mutex_unlock(&inode->i_mutex);
return err;
}
......
......@@ -14,6 +14,7 @@
#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/sched.h>
#include <linux/xattr.h>
#include <asm/uaccess.h>
......@@ -35,25 +36,32 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
flags |= FS_NODUMP_FL; /* EXT2_NODUMP_FL */
return put_user(flags, (int __user *)arg);
case HFSPLUS_IOC_EXT2_SETFLAGS: {
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(flags, (int __user *)arg))
return -EFAULT;
int err = 0;
err = mnt_want_write(filp->f_path.mnt);
if (err)
return err;
if (!is_owner_or_cap(inode)) {
err = -EACCES;
goto setflags_out;
}
if (get_user(flags, (int __user *)arg)) {
err = -EFAULT;
goto setflags_out;
}
if (flags & (FS_IMMUTABLE_FL|FS_APPEND_FL) ||
HFSPLUS_I(inode).rootflags & (HFSPLUS_FLG_IMMUTABLE|HFSPLUS_FLG_APPEND)) {
if (!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto setflags_out;
}
}
/* don't silently ignore unsupported ext2 flags */
if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL))
return -EOPNOTSUPP;
if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
err = -EOPNOTSUPP;
goto setflags_out;
}
if (flags & FS_IMMUTABLE_FL) { /* EXT2_IMMUTABLE_FL */
inode->i_flags |= S_IMMUTABLE;
HFSPLUS_I(inode).rootflags |= HFSPLUS_FLG_IMMUTABLE;
......@@ -75,7 +83,9 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
return 0;
setflags_out:
mnt_drop_write(filp->f_path.mnt);
return err;
}
default:
return -ENOTTY;
......
......@@ -8,6 +8,7 @@
#include <linux/fs.h>
#include <linux/ctype.h>