Blob Blame History Raw
From f87391558acf816b48f325a493d81d45dec40da0 Mon Sep 17 00:00:00 2001
From: Corentin Labbe <clabbe.montjoie@gmail.com>
Date: Thu, 18 Apr 2019 10:17:34 +0200
Subject: [PATCH] crypto: sun4i-ss - Fix invalid calculation of hash end
Git-commit: f87391558acf816b48f325a493d81d45dec40da0
Patch-mainline: v5.2-rc1
References: bsc#1051510

When nbytes < 4, end is wronlgy set to a negative value which, due to
uint, is then interpreted to a large value leading to a deadlock in the
following code.

This patch fix this problem.

Fixes: 6298e948215f ("crypto: sunxi-ss - Add Allwinner Security System crypto accelerator")
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/crypto/sunxi-ss/sun4i-ss-hash.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
@@ -250,7 +250,10 @@ static int sun4i_hash(struct ahash_reque
 		}
 	} else {
 		/* Since we have the flag final, we can go up to modulo 4 */
-		end = ((areq->nbytes + op->len) / 4) * 4 - op->len;
+		if (areq->nbytes < 4)
+			end = 0;
+		else
+			end = ((areq->nbytes + op->len) / 4) * 4 - op->len;
 	}
 
 	/* TODO if SGlen % 4 and op->len == 0 then DMA */