Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Lots of bug fixes and cleanups"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
  ext4: remove unused variable
  ext4: use journal inode to determine journal overhead
  ext4: create function to read journal inode
  ext4: unmap metadata when zeroing blocks
  ext4: remove plugging from ext4_file_write_iter()
  ext4: allow unlocked direct IO when pages are cached
  ext4: require encryption feature for EXT4_IOC_SET_ENCRYPTION_POLICY
  fscrypto: use standard macros to compute length of fname ciphertext
  ext4: do not unnecessarily null-terminate encrypted symlink data
  ext4: release bh in make_indexed_dir
  ext4: Allow parallel DIO reads
  ext4: allow DAX writeback for hole punch
  jbd2: fix lockdep annotation in add_transaction_credits()
  blockgroup_lock.h: simplify definition of NR_BG_LOCKS
  blockgroup_lock.h: remove debris from bgl_lock_ptr() conversion
  fscrypto: make filename crypto functions return 0 on success
  fscrypto: rename completion callbacks to reflect usage
  fscrypto: remove unnecessary includes
  fscrypto: improved validation when loading inode encryption metadata
  ext4: fix memory leak when symlink decryption fails
  ...

3 files changed, 93 insertions, 74 deletions

diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index c502c116924c..61057b7dbddb 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -28,7 +28,6 @@
 #include <linux/dcache.h>
 #include <linux/namei.h>
 #include <linux/fscrypto.h>
-#include <linux/ecryptfs.h>
 
 static unsigned int num_prealloc_crypto_pages = 32;
 static unsigned int num_prealloc_crypto_ctxs = 128;
@@ -128,11 +127,11 @@ struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode, gfp_t gfp_flags)
 EXPORT_SYMBOL(fscrypt_get_ctx);
 
 /**
- * fscrypt_complete() - The completion callback for page encryption
- * @req: The asynchronous encryption request context
- * @res: The result of the encryption operation
+ * page_crypt_complete() - completion callback for page crypto
+ * @req: The asynchronous cipher request context
+ * @res: The result of the cipher operation
  */
-static void fscrypt_complete(struct crypto_async_request *req, int res)
+static void page_crypt_complete(struct crypto_async_request *req, int res)
 {
 	struct fscrypt_completion_result *ecr = req->data;
 
@@ -170,7 +169,7 @@ static int do_page_crypto(struct inode *inode,
 
 	skcipher_request_set_callback(
 		req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		fscrypt_complete, &ecr);
+		page_crypt_complete, &ecr);
 
 	BUILD_BUG_ON(FS_XTS_TWEAK_SIZE < sizeof(index));
 	memcpy(xts_tweak, &index, sizeof(index));
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 5d6d49113efa..9a28133ac3b8 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -10,21 +10,16 @@
  * This has not yet undergone a rigorous security audit.
  */
 
-#include <keys/encrypted-type.h>
-#include <keys/user-type.h>
 #include <linux/scatterlist.h>
 #include <linux/ratelimit.h>
 #include <linux/fscrypto.h>
 
-static u32 size_round_up(size_t size, size_t blksize)
-{
-	return ((size + blksize - 1) / blksize) * blksize;
-}
-
 /**
- * dir_crypt_complete() -
+ * fname_crypt_complete() - completion callback for filename crypto
+ * @req: The asynchronous cipher request context
+ * @res: The result of the cipher operation
  */
-static void dir_crypt_complete(struct crypto_async_request *req, int res)
+static void fname_crypt_complete(struct crypto_async_request *req, int res)
 {
 	struct fscrypt_completion_result *ecr = req->data;
 
@@ -35,11 +30,11 @@ static void dir_crypt_complete(struct crypto_async_request *req, int res)
 }
 
 /**
- * fname_encrypt() -
+ * fname_encrypt() - encrypt a filename
  *
- * This function encrypts the input filename, and returns the length of the
- * ciphertext. Errors are returned as negative numbers.  We trust the caller to
- * allocate sufficient memory to oname string.
+ * The caller must have allocated sufficient memory for the @oname string.
+ *
+ * Return: 0 on success, -errno on failure
  */
 static int fname_encrypt(struct inode *inode,
 			const struct qstr *iname, struct fscrypt_str *oname)
@@ -60,10 +55,9 @@ static int fname_encrypt(struct inode *inode,
 	if (iname->len <= 0 || iname->len > lim)
 		return -EIO;
 
-	ciphertext_len = (iname->len < FS_CRYPTO_BLOCK_SIZE) ?
-					FS_CRYPTO_BLOCK_SIZE : iname->len;
-	ciphertext_len = size_round_up(ciphertext_len, padding);
-	ciphertext_len = (ciphertext_len > lim) ? lim : ciphertext_len;
+	ciphertext_len = max(iname->len, (u32)FS_CRYPTO_BLOCK_SIZE);
+	ciphertext_len = round_up(ciphertext_len, padding);
+	ciphertext_len = min(ciphertext_len, lim);
 
 	if (ciphertext_len <= sizeof(buf)) {
 		workbuf = buf;
@@ -84,7 +78,7 @@ static int fname_encrypt(struct inode *inode,
 	}
 	skcipher_request_set_callback(req,
 			CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-			dir_crypt_complete, &ecr);
+			fname_crypt_complete, &ecr);
 
 	/* Copy the input */
 	memcpy(workbuf, iname->name, iname->len);
@@ -105,20 +99,22 @@ static int fname_encrypt(struct inode *inode,
 	}
 	kfree(alloc_buf);
 	skcipher_request_free(req);
-	if (res < 0)
+	if (res < 0) {
 		printk_ratelimited(KERN_ERR
 				"%s: Error (error code %d)\n", __func__, res);
+		return res;
+	}
 
 	oname->len = ciphertext_len;
-	return res;
+	return 0;
 }
 
-/*
- * fname_decrypt()
- *	This function decrypts the input filename, and returns
- *	the length of the plaintext.
- *	Errors are returned as negative numbers.
- *	We trust the caller to allocate sufficient memory to oname string.
+/**
+ * fname_decrypt() - decrypt a filename
+ *
+ * The caller must have allocated sufficient memory for the @oname string.
+ *
+ * Return: 0 on success, -errno on failure
  */
 static int fname_decrypt(struct inode *inode,
 				const struct fscrypt_str *iname,
@@ -146,7 +142,7 @@ static int fname_decrypt(struct inode *inode,
 	}
 	skcipher_request_set_callback(req,
 		CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
-		dir_crypt_complete, &ecr);
+		fname_crypt_complete, &ecr);
 
 	/* Initialize IV */
 	memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
@@ -168,7 +164,7 @@ static int fname_decrypt(struct inode *inode,
 	}
 
 	oname->len = strnlen(oname->name, iname->len);
-	return oname->len;
+	return 0;
 }
 
 static const char *lookup_table =
@@ -231,9 +227,8 @@ u32 fscrypt_fname_encrypted_size(struct inode *inode, u32 ilen)
 
 	if (ci)
 		padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
-	if (ilen < FS_CRYPTO_BLOCK_SIZE)
-		ilen = FS_CRYPTO_BLOCK_SIZE;
-	return size_round_up(ilen, padding);
+	ilen = max(ilen, (u32)FS_CRYPTO_BLOCK_SIZE);
+	return round_up(ilen, padding);
 }
 EXPORT_SYMBOL(fscrypt_fname_encrypted_size);
 
@@ -279,6 +274,10 @@ EXPORT_SYMBOL(fscrypt_fname_free_buffer);
 /**
  * fscrypt_fname_disk_to_usr() - converts a filename from disk space to user
  * space
+ *
+ * The caller must have allocated sufficient memory for the @oname string.
+ *
+ * Return: 0 on success, -errno on failure
  */
 int fscrypt_fname_disk_to_usr(struct inode *inode,
 			u32 hash, u32 minor_hash,
@@ -287,13 +286,12 @@ int fscrypt_fname_disk_to_usr(struct inode *inode,
 {
 	const struct qstr qname = FSTR_TO_QSTR(iname);
 	char buf[24];
-	int ret;
 
 	if (fscrypt_is_dot_dotdot(&qname)) {
 		oname->name[0] = '.';
 		oname->name[iname->len - 1] = '.';
 		oname->len = iname->len;
-		return oname->len;
+		return 0;
 	}
 
 	if (iname->len < FS_CRYPTO_BLOCK_SIZE)
@@ -303,9 +301,9 @@ int fscrypt_fname_disk_to_usr(struct inode *inode,
 		return fname_decrypt(inode, iname, oname);
 
 	if (iname->len <= FS_FNAME_CRYPTO_DIGEST_SIZE) {
-		ret = digest_encode(iname->name, iname->len, oname->name);
-		oname->len = ret;
-		return ret;
+		oname->len = digest_encode(iname->name, iname->len,
+					   oname->name);
+		return 0;
 	}
 	if (hash) {
 		memcpy(buf, &hash, 4);
@@ -315,15 +313,18 @@ int fscrypt_fname_disk_to_usr(struct inode *inode,
 	}
 	memcpy(buf + 8, iname->name + iname->len - 16, 16);
 	oname->name[0] = '_';
-	ret = digest_encode(buf, 24, oname->name + 1);
-	oname->len = ret + 1;
-	return ret + 1;
+	oname->len = 1 + digest_encode(buf, 24, oname->name + 1);
+	return 0;
 }
 EXPORT_SYMBOL(fscrypt_fname_disk_to_usr);
 
 /**
  * fscrypt_fname_usr_to_disk() - converts a filename from user space to disk
  * space
+ *
+ * The caller must have allocated sufficient memory for the @oname string.
+ *
+ * Return: 0 on success, -errno on failure
  */
 int fscrypt_fname_usr_to_disk(struct inode *inode,
 			const struct qstr *iname,
@@ -333,7 +334,7 @@ int fscrypt_fname_usr_to_disk(struct inode *inode,
 		oname->name[0] = '.';
 		oname->name[iname->len - 1] = '.';
 		oname->len = iname->len;
-		return oname->len;
+		return 0;
 	}
 	if (inode->i_crypt_info)
 		return fname_encrypt(inode, iname, oname);
@@ -367,10 +368,10 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
 	if (dir->i_crypt_info) {
 		ret = fscrypt_fname_alloc_buffer(dir, iname->len,
 							&fname->crypto_buf);
-		if (ret < 0)
+		if (ret)
 			return ret;
 		ret = fname_encrypt(dir, iname, &fname->crypto_buf);
-		if (ret < 0)
+		if (ret)
 			goto errout;
 		fname->disk_name.name = fname->crypto_buf.name;
 		fname->disk_name.len = fname->crypto_buf.len;
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 1ac263eddc4e..82f0285f5d08 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -8,11 +8,8 @@
  * Written by Michael Halcrow, Ildar Muslukhov, and Uday Savagaonkar, 2015.
  */
 
-#include <keys/encrypted-type.h>
 #include <keys/user-type.h>
-#include <linux/random.h>
 #include <linux/scatterlist.h>
-#include <uapi/linux/keyctl.h>
 #include <linux/fscrypto.h>
 
 static void derive_crypt_complete(struct crypto_async_request *req, int rc)
@@ -139,6 +136,38 @@ out:
 	return res;
 }
 
+static int determine_cipher_type(struct fscrypt_info *ci, struct inode *inode,
+				 const char **cipher_str_ret, int *keysize_ret)
+{
+	if (S_ISREG(inode->i_mode)) {
+		if (ci->ci_data_mode == FS_ENCRYPTION_MODE_AES_256_XTS) {
+			*cipher_str_ret = "xts(aes)";
+			*keysize_ret = FS_AES_256_XTS_KEY_SIZE;
+			return 0;
+		}
+		pr_warn_once("fscrypto: unsupported contents encryption mode "
+			     "%d for inode %lu\n",
+			     ci->ci_data_mode, inode->i_ino);
+		return -ENOKEY;
+	}
+
+	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) {
+		if (ci->ci_filename_mode == FS_ENCRYPTION_MODE_AES_256_CTS) {
+			*cipher_str_ret = "cts(cbc(aes))";
+			*keysize_ret = FS_AES_256_CTS_KEY_SIZE;
+			return 0;
+		}
+		pr_warn_once("fscrypto: unsupported filenames encryption mode "
+			     "%d for inode %lu\n",
+			     ci->ci_filename_mode, inode->i_ino);
+		return -ENOKEY;
+	}
+
+	pr_warn_once("fscrypto: unsupported file type %d for inode %lu\n",
+		     (inode->i_mode & S_IFMT), inode->i_ino);
+	return -ENOKEY;
+}
+
 static void put_crypt_info(struct fscrypt_info *ci)
 {
 	if (!ci)
@@ -155,8 +184,8 @@ int get_crypt_info(struct inode *inode)
 	struct fscrypt_context ctx;
 	struct crypto_skcipher *ctfm;
 	const char *cipher_str;
+	int keysize;
 	u8 raw_key[FS_MAX_KEY_SIZE];
-	u8 mode;
 	int res;
 
 	res = fscrypt_initialize();
@@ -179,13 +208,19 @@ retry:
 	if (res < 0) {
 		if (!fscrypt_dummy_context_enabled(inode))
 			return res;
+		ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1;
 		ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS;
 		ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;
 		ctx.flags = 0;
 	} else if (res != sizeof(ctx)) {
 		return -EINVAL;
 	}
-	res = 0;
+
+	if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)
+		return -EINVAL;
+
+	if (ctx.flags & ~FS_POLICY_FLAGS_VALID)
+		return -EINVAL;
 
 	crypt_info = kmem_cache_alloc(fscrypt_info_cachep, GFP_NOFS);
 	if (!crypt_info)
@@ -198,27 +233,11 @@ retry:
 	crypt_info->ci_keyring_key = NULL;
 	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
 				sizeof(crypt_info->ci_master_key));
-	if (S_ISREG(inode->i_mode))
-		mode = crypt_info->ci_data_mode;
-	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		mode = crypt_info->ci_filename_mode;
-	else
-		BUG();
-
-	switch (mode) {
-	case FS_ENCRYPTION_MODE_AES_256_XTS:
-		cipher_str = "xts(aes)";
-		break;
-	case FS_ENCRYPTION_MODE_AES_256_CTS:
-		cipher_str = "cts(cbc(aes))";
-		break;
-	default:
-		printk_once(KERN_WARNING
-			    "%s: unsupported key mode %d (ino %u)\n",
-			    __func__, mode, (unsigned) inode->i_ino);
-		res = -ENOKEY;
+
+	res = determine_cipher_type(crypt_info, inode, &cipher_str, &keysize);
+	if (res)
 		goto out;
-	}
+
 	if (fscrypt_dummy_context_enabled(inode)) {
 		memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
 		goto got_key;
@@ -253,7 +272,7 @@ got_key:
 	crypt_info->ci_ctfm = ctfm;
 	crypto_skcipher_clear_flags(ctfm, ~0);
 	crypto_skcipher_set_flags(ctfm, CRYPTO_TFM_REQ_WEAK_KEY);
-	res = crypto_skcipher_setkey(ctfm, raw_key, fscrypt_key_size(mode));
+	res = crypto_skcipher_setkey(ctfm, raw_key, keysize);
 	if (res)
 		goto out;