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Commit e709e9df authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4 crypto: encrypt tmpfile located in encryption protected directory 



Factor out calls to ext4_inherit_context() and move them to
__ext4_new_inode(); this fixes a problem where ext4_tmpfile() wasn't
calling calling ext4_inherit_context(), so the temporary file wasn't
getting protected.  Since the blocks for the tmpfile could end up on
disk, they really should be protected if the tmpfile is created within
the context of an encrypted directory.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 6bc445e0

fs/ext4/ext4.h

+9 −0
Original line number Diff line number Diff line
@@ -2149,6 +2149,11 @@ static inline int ext4_get_encryption_info(struct inode *inode) 
	return 0;

}



static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)

{

	return EXT4_I(inode)->i_crypt_info;

}



#else

static inline int ext4_has_encryption_key(struct inode *inode)

{
@@ -2158,6 +2163,10 @@ static inline int ext4_get_encryption_info(struct inode *inode) 
{

	return 0;

}

static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)

{

	return NULL;

}

#endif

fs/ext4/ialloc.c

+20 −6
Original line number Diff line number Diff line
@@ -726,11 +726,25 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir, 
	ext4_group_t i;

	ext4_group_t flex_group;

	struct ext4_group_info *grp;

	int encrypt = 0;



	/* Cannot create files in a deleted directory */

	if (!dir || !dir->i_nlink)

		return ERR_PTR(-EPERM);



	if ((ext4_encrypted_inode(dir) ||

	     DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) &&

	    (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {

		err = ext4_get_encryption_info(dir);

		if (err)

			return ERR_PTR(err);

		if (ext4_encryption_info(dir) == NULL)

			return ERR_PTR(-EPERM);

		if (!handle)

			nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb);

		encrypt = 1;

	}



	sb = dir->i_sb;

	ngroups = ext4_get_groups_count(sb);

	trace_ext4_request_inode(dir, mode);
@@ -996,12 +1010,6 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir, 
	ei->i_block_group = group;

	ei->i_last_alloc_group = ~0;



	/* If the directory encrypted, then we should encrypt the inode. */

	if ((S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) &&

	    (ext4_encrypted_inode(dir) ||

	     DUMMY_ENCRYPTION_ENABLED(sbi)))

		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);



	ext4_set_inode_flags(inode);

	if (IS_DIRSYNC(inode))

		ext4_handle_sync(handle);
@@ -1063,6 +1071,12 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir, 
		ei->i_datasync_tid = handle->h_transaction->t_tid;

	}



	if (encrypt) {

		err = ext4_inherit_context(dir, inode);

		if (err)

			goto fail_free_drop;

	}



	err = ext4_mark_inode_dirty(handle, inode);

	if (err) {

		ext4_std_error(sb, err);

fs/ext4/namei.c

+1 −28
Original line number Diff line number Diff line
@@ -2437,19 +2437,6 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, 
		inode->i_op = &ext4_file_inode_operations;

		inode->i_fop = &ext4_file_operations;

		ext4_set_aops(inode);

		err = 0;

#ifdef CONFIG_EXT4_FS_ENCRYPTION

		if (!err && (ext4_encrypted_inode(dir) ||

			     DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb)))) {

			err = ext4_inherit_context(dir, inode);

			if (err) {

				clear_nlink(inode);

				unlock_new_inode(inode);

				iput(inode);

			}

		}

#endif

		if (!err)

		err = ext4_add_nondir(handle, dentry, inode);

		if (!err && IS_DIRSYNC(dir))

			ext4_handle_sync(handle);
@@ -2631,14 +2618,6 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) 
	err = ext4_init_new_dir(handle, dir, inode);

	if (err)

		goto out_clear_inode;

#ifdef CONFIG_EXT4_FS_ENCRYPTION

	if (ext4_encrypted_inode(dir) ||

	    DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) {

		err = ext4_inherit_context(dir, inode);

		if (err)

			goto out_clear_inode;

	}

#endif

	err = ext4_mark_inode_dirty(handle, inode);

	if (!err)

		err = ext4_add_entry(handle, dentry, inode);
@@ -3106,12 +3085,6 @@ static int ext4_symlink(struct inode *dir, 
			err = -ENOMEM;

			goto err_drop_inode;

		}

		err = ext4_inherit_context(dir, inode);

		if (err)

			goto err_drop_inode;

		err = ext4_get_encryption_info(inode);

		if (err)

			goto err_drop_inode;

		istr.name = (const unsigned char *) symname;

		istr.len = len;

		ostr.name = sd->encrypted_path;