Patch "crypto: sun4i-ss - linearize buffers content must be kept" has been added to the 5.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    crypto: sun4i-ss - linearize buffers content must be kept

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-sun4i-ss-linearize-buffers-content-must-be-ke.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit fa69a026bc0d0d803dadf2ee980b4de444658ff7
Author: Corentin Labbe <clabbe@xxxxxxxxxxxx>
Date:   Mon Dec 14 20:02:25 2020 +0000

    crypto: sun4i-ss - linearize buffers content must be kept
    
    [ Upstream commit 583513510a7acd2306787865bcd19ebb2f629d42 ]
    
    When running the non-optimized cipher function, SS produce partial random
    output.
    This is due to linearize buffers being reseted after each loop.
    
    For preserving stack, instead of moving them back to start of function,
    I move them in sun4i_ss_ctx.
    
    Fixes: 8d3bcb9900ca ("crypto: sun4i-ss - reduce stack usage")
    Signed-off-by: Corentin Labbe <clabbe@xxxxxxxxxxxx>
    Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
index 7e5e092a23b3c..4145a046274e5 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
@@ -235,8 +235,6 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 
 	while (oleft) {
 		if (ileft) {
-			char buf[4 * SS_RX_MAX];/* buffer for linearize SG src */
-
 			/*
 			 * todo is the number of consecutive 4byte word that we
 			 * can read from current SG
@@ -258,12 +256,12 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 				 */
 				todo = min(rx_cnt * 4 - ob, ileft);
 				todo = min_t(size_t, todo, mi.length - oi);
-				memcpy(buf + ob, mi.addr + oi, todo);
+				memcpy(ss->buf + ob, mi.addr + oi, todo);
 				ileft -= todo;
 				oi += todo;
 				ob += todo;
 				if (!(ob % 4)) {
-					writesl(ss->base + SS_RXFIFO, buf,
+					writesl(ss->base + SS_RXFIFO, ss->buf,
 						ob / 4);
 					ob = 0;
 				}
@@ -297,13 +295,11 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 				oo = 0;
 			}
 		} else {
-			char bufo[4 * SS_TX_MAX]; /* buffer for linearize SG dst */
-
 			/*
 			 * read obl bytes in bufo, we read at maximum for
 			 * emptying the device
 			 */
-			readsl(ss->base + SS_TXFIFO, bufo, tx_cnt);
+			readsl(ss->base + SS_TXFIFO, ss->bufo, tx_cnt);
 			obl = tx_cnt * 4;
 			obo = 0;
 			do {
@@ -315,7 +311,7 @@ static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 				 */
 				todo = min_t(size_t,
 					     mo.length - oo, obl - obo);
-				memcpy(mo.addr + oo, bufo + obo, todo);
+				memcpy(mo.addr + oo, ss->bufo + obo, todo);
 				oleft -= todo;
 				obo += todo;
 				oo += todo;
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss.h b/drivers/crypto/sunxi-ss/sun4i-ss.h
index 35a27a7145f84..9a2adc130d9aa 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss.h
+++ b/drivers/crypto/sunxi-ss/sun4i-ss.h
@@ -138,6 +138,8 @@ struct sun4i_ss_ctx {
 	struct reset_control *reset;
 	struct device *dev;
 	struct resource *res;
+	char buf[4 * SS_RX_MAX];/* buffer for linearize SG src */
+	char bufo[4 * SS_TX_MAX]; /* buffer for linearize SG dst */
 	spinlock_t slock; /* control the use of the device */
 #ifdef CONFIG_CRYPTO_DEV_SUN4I_SS_PRNG
 	u32 seed[SS_SEED_LEN / BITS_PER_LONG];