[PATCH 4.19 128/280] crypto: morus - fix handling chunked inputs

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@xxxxxxxxxx>

commit d644f1c8746ed24f81075480f9e9cb3777ae8d65 upstream.

The generic MORUS implementations all fail the improved AEAD tests
because they produce the wrong result with some data layouts.  The issue
is that they assume that if the skcipher_walk API gives 'nbytes' not
aligned to the walksize (a.k.a. walk.stride), then it is the end of the
data.  In fact, this can happen before the end.  Fix them.

Fixes: 396be41f16fd ("crypto: morus - Add generic MORUS AEAD implementations")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.18+
Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 crypto/morus1280.c |   13 +++++++------
 crypto/morus640.c  |   13 +++++++------
 2 files changed, 14 insertions(+), 12 deletions(-)

--- a/crypto/morus1280.c
+++ b/crypto/morus1280.c
@@ -366,18 +366,19 @@ static void crypto_morus1280_process_cry
 					   const struct morus1280_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *dst;
-	const u8 *src;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, walk.nbytes);
+		if (nbytes < walk.total)
+			nbytes = round_down(nbytes, walk.stride);
 
-		skcipher_walk_done(&walk, 0);
+		ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+				 nbytes);
+
+		skcipher_walk_done(&walk, walk.nbytes - nbytes);
 	}
 }
 
--- a/crypto/morus640.c
+++ b/crypto/morus640.c
@@ -365,18 +365,19 @@ static void crypto_morus640_process_cryp
 					  const struct morus640_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *dst;
-	const u8 *src;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, walk.nbytes);
+		if (nbytes < walk.total)
+			nbytes = round_down(nbytes, walk.stride);
 
-		skcipher_walk_done(&walk, 0);
+		ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+				 nbytes);
+
+		skcipher_walk_done(&walk, walk.nbytes - nbytes);
 	}
 }