3 files changed, 57 insertions, 45 deletions

diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index a45d0d630a30..d320f5197437 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -19,6 +19,8 @@
 extern int evm_initialized;
 extern char *evm_hmac;
 
+extern struct crypto_shash *hmac_tfm;
+
 /* List of EVM protected security xattrs */
 extern char *evm_config_xattrnames[];
 
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index c9902bddcb9a..5dd5b140242c 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -16,8 +16,8 @@
 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/xattr.h>
-#include <linux/scatterlist.h>
 #include <keys/encrypted-type.h>
+#include <crypto/hash.h>
 #include "evm.h"
 
 #define EVMKEY "evm-key"
@@ -25,26 +25,42 @@
 static unsigned char evmkey[MAX_KEY_SIZE];
 static int evmkey_len = MAX_KEY_SIZE;
 
-static int init_desc(struct hash_desc *desc)
+struct crypto_shash *hmac_tfm;
+
+static struct shash_desc *init_desc(void)
 {
         int rc;
-
-        desc->tfm = crypto_alloc_hash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(desc->tfm)) {
-                pr_info("Can not allocate %s (reason: %ld)\n",
-                        evm_hmac, PTR_ERR(desc->tfm));
-                rc = PTR_ERR(desc->tfm);
-                return rc;
+        struct shash_desc *desc;
+
+        if (hmac_tfm == NULL) {
+                hmac_tfm = crypto_alloc_shash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
+                if (IS_ERR(hmac_tfm)) {
+                        pr_err("Can not allocate %s (reason: %ld)\n",
+                               evm_hmac, PTR_ERR(hmac_tfm));
+                        rc = PTR_ERR(hmac_tfm);
+                        hmac_tfm = NULL;
+                        return ERR_PTR(rc);
+                }
         }
-        desc->flags = 0;
-        rc = crypto_hash_setkey(desc->tfm, evmkey, evmkey_len);
+
+        desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(hmac_tfm),
+                        GFP_KERNEL);
+        if (!desc)
+                return ERR_PTR(-ENOMEM);
+
+        desc->tfm = hmac_tfm;
+        desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+        rc = crypto_shash_setkey(hmac_tfm, evmkey, evmkey_len);
         if (rc)
                 goto out;
-        rc = crypto_hash_init(desc);
+        rc = crypto_shash_init(desc);
 out:
-        if (rc)
-                crypto_free_hash(desc->tfm);
-        return rc;
+        if (rc) {
+                kfree(desc);
+                return ERR_PTR(rc);
+        }
+        return desc;
 }
 
 /* Protect against 'cutting & pasting' security.evm xattr, include inode
@@ -53,7 +69,7 @@ out:
  * (Additional directory/file metadata needs to be added for more complete
  * protection.)
  */
-static void hmac_add_misc(struct hash_desc *desc, struct inode *inode,
+static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
                           char *digest)
 {
         struct h_misc {
@@ -63,7 +79,6 @@ static void hmac_add_misc(struct hash_desc *desc, struct inode *inode,
                 gid_t gid;
                 umode_t mode;
         } hmac_misc;
-        struct scatterlist sg[1];
 
         memset(&hmac_misc, 0, sizeof hmac_misc);
         hmac_misc.ino = inode->i_ino;
@@ -71,9 +86,8 @@ static void hmac_add_misc(struct hash_desc *desc, struct inode *inode,
         hmac_misc.uid = inode->i_uid;
         hmac_misc.gid = inode->i_gid;
         hmac_misc.mode = inode->i_mode;
-        sg_init_one(sg, &hmac_misc, sizeof hmac_misc);
-        crypto_hash_update(desc, sg, sizeof hmac_misc);
-        crypto_hash_final(desc, digest);
+        crypto_shash_update(desc, (const u8 *)&hmac_misc, sizeof hmac_misc);
+        crypto_shash_final(desc, digest);
 }
 
 /*
@@ -88,8 +102,7 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
                   char *digest)
 {
         struct inode *inode = dentry->d_inode;
-        struct hash_desc desc;
-        struct scatterlist sg[1];
+        struct shash_desc *desc;
         char **xattrname;
         size_t xattr_size = 0;
         char *xattr_value = NULL;
@@ -98,17 +111,17 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
 
         if (!inode->i_op || !inode->i_op->getxattr)
                 return -EOPNOTSUPP;
-        error = init_desc(&desc);
-        if (error)
-                return error;
+        desc = init_desc();
+        if (IS_ERR(desc))
+                return PTR_ERR(desc);
 
         error = -ENODATA;
         for (xattrname = evm_config_xattrnames; *xattrname != NULL; xattrname++) {
                 if ((req_xattr_name && req_xattr_value)
                     && !strcmp(*xattrname, req_xattr_name)) {
                         error = 0;
-                        sg_init_one(sg, req_xattr_value, req_xattr_value_len);
-                        crypto_hash_update(&desc, sg, req_xattr_value_len);
+                        crypto_shash_update(desc, (const u8 *)req_xattr_value,
+                                             req_xattr_value_len);
                         continue;
                 }
                 size = vfs_getxattr_alloc(dentry, *xattrname,
@@ -122,13 +135,13 @@ int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
 
                 error = 0;
                 xattr_size = size;
-                sg_init_one(sg, xattr_value, xattr_size);
-                crypto_hash_update(&desc, sg, xattr_size);
+                crypto_shash_update(desc, (const u8 *)xattr_value, xattr_size);
         }
-        hmac_add_misc(&desc, inode, digest);
-        kfree(xattr_value);
+        hmac_add_misc(desc, inode, digest);
+
 out:
-        crypto_free_hash(desc.tfm);
+        kfree(xattr_value);
+        kfree(desc);
         return error;
 }
 
@@ -160,20 +173,17 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
 int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr,
                   char *hmac_val)
 {
-        struct hash_desc desc;
-        struct scatterlist sg[1];
-        int error;
+        struct shash_desc *desc;
 
-        error = init_desc(&desc);
-        if (error != 0) {
+        desc = init_desc();
+        if (IS_ERR(desc)) {
                 printk(KERN_INFO "init_desc failed\n");
-                return error;
+                return PTR_ERR(desc);
         }
 
-        sg_init_one(sg, lsm_xattr->value, lsm_xattr->value_len);
-        crypto_hash_update(&desc, sg, lsm_xattr->value_len);
-        hmac_add_misc(&desc, inode, hmac_val);
-        crypto_free_hash(desc.tfm);
+        crypto_shash_update(desc, lsm_xattr->value, lsm_xattr->value_len);
+        hmac_add_misc(desc, inode, hmac_val);
+        kfree(desc);
         return 0;
 }
 
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 23486355f443..b65adb5b06c8 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -19,6 +19,7 @@
 #include <linux/xattr.h>
 #include <linux/integrity.h>
 #include <linux/evm.h>
+#include <crypto/hash.h>
 #include "evm.h"
 
 int evm_initialized;
@@ -283,12 +284,10 @@ out:
 }
 EXPORT_SYMBOL_GPL(evm_inode_init_security);
 
-static struct crypto_hash *tfm_hmac;    /* preload crypto alg */
 static int __init init_evm(void)
 {
         int error;
 
-        tfm_hmac = crypto_alloc_hash(evm_hmac, 0, CRYPTO_ALG_ASYNC);
         error = evm_init_secfs();
         if (error < 0) {
                 printk(KERN_INFO "EVM: Error registering secfs\n");
@@ -301,7 +300,8 @@ err:
 static void __exit cleanup_evm(void)
 {
         evm_cleanup_secfs();
-        crypto_free_hash(tfm_hmac);
+        if (hmac_tfm)
+                crypto_free_shash(hmac_tfm);
 }
 
 /*