Commit db717d8e authored by Eric Biggers's avatar Eric Biggers Committed by Theodore Ts'o

fscrypto: move ioctl processing more fully into common code

Multiple bugs were recently fixed in the "set encryption policy" ioctl.
To make it clear that fscrypt_process_policy() and fscrypt_get_policy()
implement ioctls and therefore their implementations must take standard
security and correctness precautions, rename them to
fscrypt_ioctl_set_policy() and fscrypt_ioctl_get_policy().  Make the
latter take in a struct file * to make it consistent with the former.
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 80481235
......@@ -93,16 +93,19 @@ static int create_encryption_context_from_policy(struct inode *inode,
return inode->i_sb->s_cop->set_context(inode, &ctx, sizeof(ctx), NULL);
}
int fscrypt_process_policy(struct file *filp,
const struct fscrypt_policy *policy)
int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
{
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
int ret;
if (copy_from_user(&policy, arg, sizeof(policy)))
return -EFAULT;
if (!inode_owner_or_capable(inode))
return -EACCES;
if (policy->version != 0)
if (policy.version != 0)
return -EINVAL;
ret = mnt_want_write_file(filp);
......@@ -120,9 +123,9 @@ int fscrypt_process_policy(struct file *filp,
ret = -ENOTEMPTY;
else
ret = create_encryption_context_from_policy(inode,
policy);
&policy);
} else if (!is_encryption_context_consistent_with_policy(inode,
policy)) {
&policy)) {
printk(KERN_WARNING
"%s: Policy inconsistent with encryption context\n",
__func__);
......@@ -134,11 +137,13 @@ int fscrypt_process_policy(struct file *filp,
mnt_drop_write_file(filp);
return ret;
}
EXPORT_SYMBOL(fscrypt_process_policy);
EXPORT_SYMBOL(fscrypt_ioctl_set_policy);
int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy)
int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
{
struct inode *inode = file_inode(filp);
struct fscrypt_context ctx;
struct fscrypt_policy policy;
int res;
if (!inode->i_sb->s_cop->get_context ||
......@@ -151,15 +156,18 @@ int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy)
if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)
return -EINVAL;
policy->version = 0;
policy->contents_encryption_mode = ctx.contents_encryption_mode;
policy->filenames_encryption_mode = ctx.filenames_encryption_mode;
policy->flags = ctx.flags;
memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor,
policy.version = 0;
policy.contents_encryption_mode = ctx.contents_encryption_mode;
policy.filenames_encryption_mode = ctx.filenames_encryption_mode;
policy.flags = ctx.flags;
memcpy(policy.master_key_descriptor, ctx.master_key_descriptor,
FS_KEY_DESCRIPTOR_SIZE);
if (copy_to_user(arg, &policy, sizeof(policy)))
return -EFAULT;
return 0;
}
EXPORT_SYMBOL(fscrypt_get_policy);
EXPORT_SYMBOL(fscrypt_ioctl_get_policy);
int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
{
......
......@@ -2338,8 +2338,8 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
#define fscrypt_pullback_bio_page fscrypt_notsupp_pullback_bio_page
#define fscrypt_restore_control_page fscrypt_notsupp_restore_control_page
#define fscrypt_zeroout_range fscrypt_notsupp_zeroout_range
#define fscrypt_process_policy fscrypt_notsupp_process_policy
#define fscrypt_get_policy fscrypt_notsupp_get_policy
#define fscrypt_ioctl_set_policy fscrypt_notsupp_ioctl_set_policy
#define fscrypt_ioctl_get_policy fscrypt_notsupp_ioctl_get_policy
#define fscrypt_has_permitted_context fscrypt_notsupp_has_permitted_context
#define fscrypt_inherit_context fscrypt_notsupp_inherit_context
#define fscrypt_get_encryption_info fscrypt_notsupp_get_encryption_info
......
......@@ -765,22 +765,12 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
}
case EXT4_IOC_PRECACHE_EXTENTS:
return ext4_ext_precache(inode);
case EXT4_IOC_SET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct fscrypt_policy policy;
case EXT4_IOC_SET_ENCRYPTION_POLICY:
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;
return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
if (copy_from_user(&policy,
(struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
return fscrypt_process_policy(filp, &policy);
#else
return -EOPNOTSUPP;
#endif
}
case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
int err, err2;
struct ext4_sb_info *sbi = EXT4_SB(sb);
......@@ -817,23 +807,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return -EFAULT;
return 0;
}
case EXT4_IOC_GET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct fscrypt_policy policy;
int err = 0;
case EXT4_IOC_GET_ENCRYPTION_POLICY:
return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
if (!ext4_encrypted_inode(inode))
return -ENOENT;
err = fscrypt_get_policy(inode, &policy);
if (err)
return err;
if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
return -EFAULT;
return 0;
#else
return -EOPNOTSUPP;
#endif
}
case EXT4_IOC_FSGETXATTR:
{
struct fsxattr fa;
......
......@@ -2453,8 +2453,8 @@ static inline bool f2fs_may_encrypt(struct inode *inode)
#define fscrypt_pullback_bio_page fscrypt_notsupp_pullback_bio_page
#define fscrypt_restore_control_page fscrypt_notsupp_restore_control_page
#define fscrypt_zeroout_range fscrypt_notsupp_zeroout_range
#define fscrypt_process_policy fscrypt_notsupp_process_policy
#define fscrypt_get_policy fscrypt_notsupp_get_policy
#define fscrypt_ioctl_set_policy fscrypt_notsupp_ioctl_set_policy
#define fscrypt_ioctl_get_policy fscrypt_notsupp_ioctl_get_policy
#define fscrypt_has_permitted_context fscrypt_notsupp_has_permitted_context
#define fscrypt_inherit_context fscrypt_notsupp_inherit_context
#define fscrypt_get_encryption_info fscrypt_notsupp_get_encryption_info
......
......@@ -1752,31 +1752,16 @@ static bool uuid_is_nonzero(__u8 u[16])
static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
{
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
return fscrypt_process_policy(filp, &policy);
return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
}
static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)
{
struct fscrypt_policy policy;
struct inode *inode = file_inode(filp);
int err;
err = fscrypt_get_policy(inode, &policy);
if (err)
return err;
if (copy_to_user((struct fscrypt_policy __user *)arg, &policy, sizeof(policy)))
return -EFAULT;
return 0;
return fscrypt_ioctl_get_policy(filp, (void __user *)arg);
}
static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
......
......@@ -259,8 +259,8 @@ extern void fscrypt_restore_control_page(struct page *);
extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
unsigned int);
/* policy.c */
extern int fscrypt_process_policy(struct file *, const struct fscrypt_policy *);
extern int fscrypt_get_policy(struct inode *, struct fscrypt_policy *);
extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
extern int fscrypt_inherit_context(struct inode *, struct inode *,
void *, bool);
......@@ -334,14 +334,14 @@ static inline int fscrypt_notsupp_zeroout_range(const struct inode *i, pgoff_t p
}
/* policy.c */
static inline int fscrypt_notsupp_process_policy(struct file *f,
const struct fscrypt_policy *p)
static inline int fscrypt_notsupp_ioctl_set_policy(struct file *f,
const void __user *arg)
{
return -EOPNOTSUPP;
}
static inline int fscrypt_notsupp_get_policy(struct inode *i,
struct fscrypt_policy *p)
static inline int fscrypt_notsupp_ioctl_get_policy(struct file *f,
void __user *arg)
{
return -EOPNOTSUPP;
}
......
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