From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Fri, 30 Sep 2016 12:39:17 +0000 (+0200)
Subject: cw1200: Don't leak memory if krealloc failes
X-Git-Tag: v3.18.128~9
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=aba29c20de48fae8ab8cf13d6a31c9a8bd5e16eb;p=profile%2Fwearable%2Fplatform%2Fkernel%2Flinux-3.18-exynos7270.git

cw1200: Don't leak memory if krealloc failes

commit 9afdd6128c39f42398041bb2e017d8df0dcebcd1 upstream.

The call to krealloc() in wsm_buf_reserve() directly assigns the newly
returned memory to buf->begin. This is all fine except when krealloc()
failes we loose the ability to free the old memory pointed to by
buf->begin. If we just create a temporary variable to assign memory to
and assign the memory to it we can mitigate the memory leak.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/cw1200/wsm.c b/drivers/net/wireless/cw1200/wsm.c
index 9e0ca30..a5ac992 100644
--- a/drivers/net/wireless/cw1200/wsm.c
+++ b/drivers/net/wireless/cw1200/wsm.c
@@ -1807,16 +1807,18 @@ static int wsm_buf_reserve(struct wsm_buf *buf, size_t extra_size)
 {
 	size_t pos = buf->data - buf->begin;
 	size_t size = pos + extra_size;
+	u8 *tmp;
 
 	size = round_up(size, FWLOAD_BLOCK_SIZE);
 
-	buf->begin = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
-	if (buf->begin) {
-		buf->data = &buf->begin[pos];
-		buf->end = &buf->begin[size];
-		return 0;
-	} else {
-		buf->end = buf->data = buf->begin;
+	tmp = krealloc(buf->begin, size, GFP_KERNEL | GFP_DMA);
+	if (!tmp) {
+		wsm_buf_deinit(buf);
 		return -ENOMEM;
 	}
+
+	buf->begin = tmp;
+	buf->data = &buf->begin[pos];
+	buf->end = &buf->begin[size];
+	return 0;
 }