[PATCH] crypto: shash - fix missed optimization in shash_ahash_digest()

[PATCH] crypto: shash - fix missed optimization in shash_ahash_digest()

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

shash_ahash_digest(), which is the ->digest() method for ahash tfms that
use an shash algorithm, has an optimization where crypto_shash_digest()
is called if the data is in a single page.  But an off-by-one error
prevented this path from being taken unless the user happened to provide
extra data in the scatterlist.  Fix it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 crypto/shash.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/shash.c b/crypto/shash.c
index 15b369c4745f6..b85930e9a7a2e 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -307,7 +307,7 @@ int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
 
 	if (nbytes &&
 	    (sg = req->src, offset = sg->offset,
-	     nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
+	     nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
 		void *data;
 
 		data = kmap_atomic(sg_page(sg));
-- 
2.21.0

Re: [PATCH] crypto: shash - fix missed optimization in shash_ahash_digest()

[Herbert Xu]

On Sun, Apr 14, 2019 at 04:23:33PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> shash_ahash_digest(), which is the ->digest() method for ahash tfms that
> use an shash algorithm, has an optimization where crypto_shash_digest()
> is called if the data is in a single page.  But an off-by-one error
> prevented this path from being taken unless the user happened to provide
> extra data in the scatterlist.  Fix it.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  crypto/shash.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt