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Commit 82d0d3e7 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4 crypto: clean up error handling in ext4_fname_setup_filename 



Fix a potential memory leak where fname->crypto_buf.name wouldn't get
freed in some error paths, and also make the error handling easier to
understand/audit.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent d87f6d78

fs/ext4/crypto_fname.c

+16 −19
Original line number Diff line number Diff line
@@ -401,7 +401,7 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, 
	      ((iname->name[1] == '.') && (iname->len == 2))))) {

		fname->disk_name.name = (unsigned char *) iname->name;

		fname->disk_name.len = iname->len;

		goto out;

		return 0;

	}

	ret = ext4_get_encryption_info(dir);

	if (ret)
@@ -411,19 +411,16 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, 
		ret = ext4_fname_crypto_alloc_buffer(dir, iname->len,

						     &fname->crypto_buf);

		if (ret < 0)

			goto out;

			return ret;

		ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf);

		if (ret < 0)

			goto out;

			goto errout;

		fname->disk_name.name = fname->crypto_buf.name;

		fname->disk_name.len = fname->crypto_buf.len;

		ret = 0;

		goto out;

	}

	if (!lookup) {

		ret = -EACCES;

		goto out;

		return 0;

	}

	if (!lookup)

		return -EACCES;



	/* We don't have the key and we are doing a lookup; decode the

	 * user-supplied name
@@ -431,19 +428,17 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, 
	if (iname->name[0] == '_')

		bigname = 1;

	if ((bigname && (iname->len != 33)) ||

	    (!bigname && (iname->len > 43))) {

		ret = -ENOENT;

	}

	    (!bigname && (iname->len > 43)))

		return -ENOENT;



	fname->crypto_buf.name = kmalloc(32, GFP_KERNEL);

	if (fname->crypto_buf.name == NULL) {

		ret = -ENOMEM;

		goto out;

	}

	if (fname->crypto_buf.name == NULL)

		return -ENOMEM;

	ret = digest_decode(iname->name + bigname, iname->len - bigname,

			    fname->crypto_buf.name);

	if (ret < 0) {

		ret = -ENOENT;

		goto out;

		goto errout;

	}

	fname->crypto_buf.len = ret;

	if (bigname) {
@@ -453,8 +448,10 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname, 
		fname->disk_name.name = fname->crypto_buf.name;

		fname->disk_name.len = fname->crypto_buf.len;

	}

	ret = 0;

out:

	return 0;

errout:

	kfree(fname->crypto_buf.name);

	fname->crypto_buf.name = NULL;

	return ret;

}