Re: [PATCH]: Fix ALIGN() macro

[Herbert Xu]

On Sat, Sep 23, 2006 at 04:36:33PM -0400, Kyle Moffett wrote:
>
> Quick question:  does "crypto_hash_init()" ever return anything other  
> than 0 or 1?  If so this is a subtle bug, as "unlikely()" is  
> implemented like this:

Good point.  It's meant to be an errno value so this is a bug.

[CRYPTO] hmac: Fix error truncation by unlikely()

The error return values are truncated by unlikely so we need to
save it first.  Thanks to Kyle Moffett for spotting this.

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
-- 
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Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
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--
diff --git a/crypto/hmac.c b/crypto/hmac.c
index d52b234..b521bcd 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -92,13 +92,17 @@ static int hmac_init(struct hash_desc *p
 	struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, sizeof(void *));
 	struct hash_desc desc;
 	struct scatterlist tmp;
+	int err;
 
 	desc.tfm = ctx->child;
 	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	sg_set_buf(&tmp, ipad, bs);
 
-	return unlikely(crypto_hash_init(&desc)) ?:
-	       crypto_hash_update(&desc, &tmp, bs);
+	err = crypto_hash_init(&desc);
+	if (unlikely(err))
+		return err;
+
+	return crypto_hash_update(&desc, &tmp, bs);
 }
 
 static int hmac_update(struct hash_desc *pdesc,
@@ -123,13 +127,17 @@ static int hmac_final(struct hash_desc *
 	struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
 	struct hash_desc desc;
 	struct scatterlist tmp;
+	int err;
 
 	desc.tfm = ctx->child;
 	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 	sg_set_buf(&tmp, opad, bs + ds);
 
-	return unlikely(crypto_hash_final(&desc, digest)) ?:
-	       crypto_hash_digest(&desc, &tmp, bs + ds, out);
+	err = crypto_hash_final(&desc, digest);
+	if (unlikely(err))
+		return err;
+
+	return crypto_hash_digest(&desc, &tmp, bs + ds, out);
 }
 
 static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,
@@ -145,6 +153,7 @@ static int hmac_digest(struct hash_desc 
 	struct hash_desc desc;
 	struct scatterlist sg1[2];
 	struct scatterlist sg2[1];
+	int err;
 
 	desc.tfm = ctx->child;
 	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
@@ -154,8 +163,11 @@ static int hmac_digest(struct hash_desc 
 	sg1[1].length = 0;
 	sg_set_buf(sg2, opad, bs + ds);
 
-	return unlikely(crypto_hash_digest(&desc, sg1, nbytes + bs, digest)) ?:
-	       crypto_hash_digest(&desc, sg2, bs + ds, out);
+	err = crypto_hash_digest(&desc, sg1, nbytes + bs, digest);
+	if (unlikely(err))
+		return err;
+
+	return crypto_hash_digest(&desc, sg2, bs + ds, out);
 }
 
 static int hmac_init_tfm(struct crypto_tfm *tfm)
-
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