[CRYPTO] api: Handle unaligned keys in setkey

setkey() in {cipher,blkcipher,ablkcipher,hash}.c does not respect the
requested alignment by the algorithm. This patch fixes it. The extra
memory is allocated by kmalloc() with GFP_ATOMIC flag.

Signed-off-by: Sebastian Siewior <linux-crypto@ml.breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 25 insertions, 0 deletions

diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 8edf40c835a7..40a3dcff15bb 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -336,16 +336,41 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,
         return blkcipher_walk_next(desc, walk);
 }
 
+static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
+{
+        struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
+        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+        int ret;
+        u8 *buffer, *alignbuffer;
+        unsigned long absize;
+
+        absize = keylen + alignmask;
+        buffer = kmalloc(absize, GFP_ATOMIC);
+        if (!buffer)
+                return -ENOMEM;
+
+        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+        memcpy(alignbuffer, key, keylen);
+        ret = cipher->setkey(tfm, alignbuffer, keylen);
+        memset(alignbuffer, 0, absize);
+        kfree(buffer);
+        return ret;
+}
+
 static int setkey(struct crypto_tfm *tfm, const u8 *key,
                   unsigned int keylen)
 {
         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
+        unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 
         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
                 return -EINVAL;
         }
 
+        if ((unsigned long)key & alignmask)
+                return setkey_unaligned(tfm, key, keylen);
+
         return cipher->setkey(tfm, key, keylen);
 }