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

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

fs/crypto/policy.c

+21 −13
Original line number Diff line number Diff line
@@ -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)

{

fs/ext4/ext4.h

+2 −2
Original line number Diff line number Diff line
@@ -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

fs/ext4/ioctl.c

+5 −29
Original line number Diff line number Diff line
@@ -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;

fs/f2fs/f2fs.h

+2 −2
Original line number Diff line number Diff line
@@ -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

fs/f2fs/file.c

+2 −17
Original line number Diff line number Diff line
@@ -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)