1 files changed, 54 insertions, 6 deletions

diff --git a/crypto/api.c b/crypto/api.c
index 394169a8577d..b4728811ce3b 100644
--- a/crypto/api.c
+++ b/crypto/api.c
@@ -13,9 +13,12 @@
  * any later version.
  *
  */
+
+#include <linux/compiler.h>
 #include <linux/init.h>
 #include <linux/crypto.h>
 #include <linux/errno.h>
+#include <linux/kmod.h>
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 #include "internal.h"
@@ -33,7 +36,7 @@ static inline void crypto_alg_put(struct crypto_alg *alg)
         module_put(alg->cra_module);
 }
 
-struct crypto_alg *crypto_alg_lookup(const char *name)
+static struct crypto_alg *crypto_alg_lookup(const char *name)
 {
         struct crypto_alg *q, *alg = NULL;
 
@@ -54,6 +57,13 @@ struct crypto_alg *crypto_alg_lookup(const char *name)
         return alg;
 }
 
+/* A far more intelligent version of this is planned.  For now, just
+ * try an exact match on the name of the algorithm. */
+static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
+{
+        return try_then_request_module(crypto_alg_lookup(name), name);
+}
+
 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
 {
         tfm->crt_flags = 0;
@@ -117,20 +127,46 @@ static void crypto_exit_ops(struct crypto_tfm *tfm)
         }
 }
 
+static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
+{
+        unsigned int len;
+
+        switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
+        default:
+                BUG();
+
+        case CRYPTO_ALG_TYPE_CIPHER:
+                len = crypto_cipher_ctxsize(alg, flags);
+                break;
+                
+        case CRYPTO_ALG_TYPE_DIGEST:
+                len = crypto_digest_ctxsize(alg, flags);
+                break;
+                
+        case CRYPTO_ALG_TYPE_COMPRESS:
+                len = crypto_compress_ctxsize(alg, flags);
+                break;
+        }
+
+        return len + alg->cra_alignmask;
+}
+
 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
 {
         struct crypto_tfm *tfm = NULL;
         struct crypto_alg *alg;
+        unsigned int tfm_size;
 
         alg = crypto_alg_mod_lookup(name);
         if (alg == NULL)
                 goto out;
-        
-        tfm = kmalloc(sizeof(*tfm) + alg->cra_ctxsize, GFP_KERNEL);
+
+        tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
+        tfm = kmalloc(tfm_size, GFP_KERNEL);
         if (tfm == NULL)
                 goto out_put;
 
-        memset(tfm, 0, sizeof(*tfm) + alg->cra_ctxsize);
+        memset(tfm, 0, tfm_size);
         
         tfm->__crt_alg = alg;
         
@@ -155,8 +191,14 @@ out:
 
 void crypto_free_tfm(struct crypto_tfm *tfm)
 {
-        struct crypto_alg *alg = tfm->__crt_alg;
-        int size = sizeof(*tfm) + alg->cra_ctxsize;
+        struct crypto_alg *alg;
+        int size;
+
+        if (unlikely(!tfm))
+                return;
+
+        alg = tfm->__crt_alg;
+        size = sizeof(*tfm) + alg->cra_ctxsize;
 
         crypto_exit_ops(tfm);
         crypto_alg_put(alg);
@@ -168,6 +210,12 @@ int crypto_register_alg(struct crypto_alg *alg)
 {
         int ret = 0;
         struct crypto_alg *q;
+
+        if (alg->cra_alignmask & (alg->cra_alignmask + 1))
+                return -EINVAL;
+
+        if (alg->cra_alignmask > PAGE_SIZE)
+                return -EINVAL;
         
         down_write(&crypto_alg_sem);