From: Domen Puncer <domen.puncer@telargo.com>
Date: Wed, 23 May 2007 20:57:39 +0000 (-0700)
Subject: spi/spidev: check message size before copying
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=da90fa8ff671a0139772ec3b3e82c06077e82122;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

spi/spidev: check message size before copying

Message size needs to be checked before copying, or bad things could
happen.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 225d6b2f82dd..bcfef04f547e 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -168,6 +168,12 @@ static int spidev_message(struct spidev_data *spidev,
 			n--, k_tmp++, u_tmp++) {
 		k_tmp->len = u_tmp->len;
 
+		total += k_tmp->len;
+		if (total > bufsiz) {
+			status = -EMSGSIZE;
+			goto done;
+		}
+
 		if (u_tmp->rx_buf) {
 			k_tmp->rx_buf = buf;
 			if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
@@ -179,12 +185,6 @@ static int spidev_message(struct spidev_data *spidev,
 					u_tmp->len))
 				goto done;
 		}
-
-		total += k_tmp->len;
-		if (total > bufsiz) {
-			status = -EMSGSIZE;
-			goto done;
-		}
 		buf += k_tmp->len;
 
 		k_tmp->cs_change = !!u_tmp->cs_change;