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-rw-r--r--fs/crypto/crypto.c26
-rw-r--r--fs/crypto/fname.c132
-rw-r--r--fs/crypto/keyinfo.c87
-rw-r--r--fs/crypto/policy.c4
4 files changed, 136 insertions, 113 deletions
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index c502c116924c..98f87fe8f186 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;
@@ -152,7 +151,10 @@ static int do_page_crypto(struct inode *inode,
struct page *src_page, struct page *dest_page,
gfp_t gfp_flags)
{
- u8 xts_tweak[FS_XTS_TWEAK_SIZE];
+ struct {
+ __le64 index;
+ u8 padding[FS_XTS_TWEAK_SIZE - sizeof(__le64)];
+ } xts_tweak;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct scatterlist dst, src;
@@ -170,19 +172,17 @@ 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));
- memset(&xts_tweak[sizeof(index)], 0,
- FS_XTS_TWEAK_SIZE - sizeof(index));
+ BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE);
+ xts_tweak.index = cpu_to_le64(index);
+ memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding));
sg_init_table(&dst, 1);
sg_set_page(&dst, dest_page, PAGE_SIZE, 0);
sg_init_table(&src, 1);
sg_set_page(&src, src_page, PAGE_SIZE, 0);
- skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE,
- xts_tweak);
+ skcipher_request_set_crypt(req, &src, &dst, PAGE_SIZE, &xts_tweak);
if (rw == FS_DECRYPT)
res = crypto_skcipher_decrypt(req);
else
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 5d6d49113efa..9b774f4b50c8 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;
@@ -35,90 +30,80 @@ 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)
{
- u32 ciphertext_len;
struct skcipher_request *req = NULL;
DECLARE_FS_COMPLETION_RESULT(ecr);
struct fscrypt_info *ci = inode->i_crypt_info;
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
char iv[FS_CRYPTO_BLOCK_SIZE];
- struct scatterlist src_sg, dst_sg;
+ struct scatterlist sg;
int padding = 4 << (ci->ci_flags & FS_POLICY_FLAGS_PAD_MASK);
- char *workbuf, buf[32], *alloc_buf = NULL;
- unsigned lim;
+ unsigned int lim;
+ unsigned int cryptlen;
lim = inode->i_sb->s_cop->max_namelen(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;
+ /*
+ * Copy the filename to the output buffer for encrypting in-place and
+ * pad it with the needed number of NUL bytes.
+ */
+ cryptlen = max_t(unsigned int, iname->len, FS_CRYPTO_BLOCK_SIZE);
+ cryptlen = round_up(cryptlen, padding);
+ cryptlen = min(cryptlen, lim);
+ memcpy(oname->name, iname->name, iname->len);
+ memset(oname->name + iname->len, 0, cryptlen - iname->len);
- if (ciphertext_len <= sizeof(buf)) {
- workbuf = buf;
- } else {
- alloc_buf = kmalloc(ciphertext_len, GFP_NOFS);
- if (!alloc_buf)
- return -ENOMEM;
- workbuf = alloc_buf;
- }
+ /* Initialize the IV */
+ memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
- /* Allocate request */
+ /* Set up the encryption request */
req = skcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
- "%s: crypto_request_alloc() failed\n", __func__);
- kfree(alloc_buf);
+ "%s: skcipher_request_alloc() failed\n", __func__);
return -ENOMEM;
}
skcipher_request_set_callback(req,
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
- dir_crypt_complete, &ecr);
-
- /* Copy the input */
- memcpy(workbuf, iname->name, iname->len);
- if (iname->len < ciphertext_len)
- memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
+ fname_crypt_complete, &ecr);
+ sg_init_one(&sg, oname->name, cryptlen);
+ skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
- /* Initialize IV */
- memset(iv, 0, FS_CRYPTO_BLOCK_SIZE);
-
- /* Create encryption request */
- sg_init_one(&src_sg, workbuf, ciphertext_len);
- sg_init_one(&dst_sg, oname->name, ciphertext_len);
- skcipher_request_set_crypt(req, &src_sg, &dst_sg, ciphertext_len, iv);
+ /* Do the encryption */
res = crypto_skcipher_encrypt(req);
if (res == -EINPROGRESS || res == -EBUSY) {
+ /* Request is being completed asynchronously; wait for it */
wait_for_completion(&ecr.completion);
res = ecr.res;
}
- 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;
+ oname->len = cryptlen;
+ 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 +131,7 @@ 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 +153,7 @@ 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 +216,8 @@ 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 +263,10 @@ 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 +275,12 @@ 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 +290,9 @@ 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 +302,18 @@ 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 +323,7 @@ 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 +357,10 @@ 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..67fb6d8876d0 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;
- u8 raw_key[FS_MAX_KEY_SIZE];
- u8 mode;
+ int keysize;
+ u8 *raw_key = NULL;
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 +233,20 @@ 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;
- }
+
+ /*
+ * This cannot be a stack buffer because it is passed to the scatterlist
+ * crypto API as part of key derivation.
+ */
+ res = -ENOMEM;
+ raw_key = kmalloc(FS_MAX_KEY_SIZE, GFP_NOFS);
+ if (!raw_key)
+ goto out;
+
if (fscrypt_dummy_context_enabled(inode)) {
memset(raw_key, 0x42, FS_AES_256_XTS_KEY_SIZE);
goto got_key;
@@ -253,11 +281,12 @@ 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;
- memzero_explicit(raw_key, sizeof(raw_key));
+ kzfree(raw_key);
+ raw_key = NULL;
if (cmpxchg(&inode->i_crypt_info, NULL, crypt_info) != NULL) {
put_crypt_info(crypt_info);
goto retry;
@@ -268,7 +297,7 @@ out:
if (res == -ENOKEY)
res = 0;
put_crypt_info(crypt_info);
- memzero_explicit(raw_key, sizeof(raw_key));
+ kzfree(raw_key);
return res;
}
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index ed115acb5dee..6865663aac69 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -109,6 +109,8 @@ int fscrypt_process_policy(struct file *filp,
if (ret)
return ret;
+ inode_lock(inode);
+
if (!inode_has_encryption_context(inode)) {
if (!S_ISDIR(inode->i_mode))
ret = -EINVAL;
@@ -127,6 +129,8 @@ int fscrypt_process_policy(struct file *filp,
ret = -EINVAL;
}
+ inode_unlock(inode);
+
mnt_drop_write_file(filp);
return ret;
}
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