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-rw-r--r--fs/crypto/crypto.c15
-rw-r--r--fs/crypto/fname.c53
-rw-r--r--fs/crypto/keyinfo.c16
-rw-r--r--fs/crypto/policy.c4
4 files changed, 46 insertions, 42 deletions
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 61057b7dbddb..98f87fe8f186 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -151,7 +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;
@@ -171,17 +174,15 @@ static int do_page_crypto(struct inode *inode,
req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
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 9a28133ac3b8..9b774f4b50c8 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -39,65 +39,54 @@ static void fname_crypt_complete(struct crypto_async_request *req, int res)
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 = max(iname->len, (u32)FS_CRYPTO_BLOCK_SIZE);
- ciphertext_len = round_up(ciphertext_len, padding);
- ciphertext_len = min(ciphertext_len, lim);
+ /*
+ * 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,
fname_crypt_complete, &ecr);
+ sg_init_one(&sg, oname->name, cryptlen);
+ skcipher_request_set_crypt(req, &sg, &sg, cryptlen, iv);
- /* Copy the input */
- memcpy(workbuf, iname->name, iname->len);
- if (iname->len < ciphertext_len)
- memset(workbuf + iname->len, 0, ciphertext_len - iname->len);
-
- /* 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) {
printk_ratelimited(KERN_ERR
@@ -105,7 +94,7 @@ static int fname_encrypt(struct inode *inode,
return res;
}
- oname->len = ciphertext_len;
+ oname->len = cryptlen;
return 0;
}
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 82f0285f5d08..67fb6d8876d0 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -185,7 +185,7 @@ int get_crypt_info(struct inode *inode)
struct crypto_skcipher *ctfm;
const char *cipher_str;
int keysize;
- u8 raw_key[FS_MAX_KEY_SIZE];
+ u8 *raw_key = NULL;
int res;
res = fscrypt_initialize();
@@ -238,6 +238,15 @@ retry:
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;
@@ -276,7 +285,8 @@ got_key:
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;
@@ -287,7 +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;
}