[PATCH 4.15 23/23] crypto: tcrypt - fix S/G table for test_aead_speed()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Robert Baronescu <robert.baronescu@nxp.com>

commit 5c6ac1d4f8fbdbed65dbeb8cf149d736409d16a1 upstream.

In case buffer length is a multiple of PAGE_SIZE,
the S/G table is incorrectly generated.
Fix this by handling buflen = k * PAGE_SIZE separately.

Signed-off-by: Robert Baronescu <robert.baronescu@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 crypto/tcrypt.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -198,11 +198,13 @@ static void sg_init_aead(struct scatterl
 	}
 
 	sg_init_table(sg, np + 1);
-	np--;
+	if (rem)
+		np--;
 	for (k = 0; k < np; k++)
 		sg_set_buf(&sg[k + 1], xbuf[k], PAGE_SIZE);
 
-	sg_set_buf(&sg[k + 1], xbuf[k], rem);
+	if (rem)
+		sg_set_buf(&sg[k + 1], xbuf[k], rem);
 }
 
 static void test_aead_speed(const char *algo, int enc, unsigned int secs,