[PATCH 5.0 037/238] crypto: aegis - fix handling chunked inputs

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

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

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

From: Eric Biggers <ebiggers@xxxxxxxxxx>

commit 0f533e67d26f228ea5dfdacc8a4bdeb487af5208 upstream.

The generic AEGIS 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: f606a88e5823 ("crypto: aegis - Add generic AEGIS 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/aegis128.c  |   14 +++++++-------
 crypto/aegis128l.c |   14 +++++++-------
 crypto/aegis256.c  |   14 +++++++-------
 3 files changed, 21 insertions(+), 21 deletions(-)

--- a/crypto/aegis128.c
+++ b/crypto/aegis128.c
@@ -290,19 +290,19 @@ static void crypto_aegis128_process_cryp
 					  const struct aegis128_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *src, *dst;
-	unsigned int chunksize;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
-		chunksize = walk.nbytes;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, chunksize);
+		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/aegis128l.c
+++ b/crypto/aegis128l.c
@@ -353,19 +353,19 @@ static void crypto_aegis128l_process_cry
 					   const struct aegis128l_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *src, *dst;
-	unsigned int chunksize;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
-		chunksize = walk.nbytes;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, chunksize);
+		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/aegis256.c
+++ b/crypto/aegis256.c
@@ -303,19 +303,19 @@ static void crypto_aegis256_process_cryp
 					  const struct aegis256_ops *ops)
 {
 	struct skcipher_walk walk;
-	u8 *src, *dst;
-	unsigned int chunksize;
 
 	ops->skcipher_walk_init(&walk, req, false);
 
 	while (walk.nbytes) {
-		src = walk.src.virt.addr;
-		dst = walk.dst.virt.addr;
-		chunksize = walk.nbytes;
+		unsigned int nbytes = walk.nbytes;
 
-		ops->crypt_chunk(state, dst, src, chunksize);
+		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);
 	}
 }