From: Christian Gromm <christian.gromm@microchip.com>
Date: Tue, 2 Feb 2021 16:21:05 +0000 (+0100)
Subject: staging: most: sound: add sanity check for function argument
X-Git-Tag: v4.4.260~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ec6136f4118c715fc3f0791b8260f30f3d0b0ad;p=thirdparty%2Fkernel%2Fstable.git

staging: most: sound: add sanity check for function argument

[ Upstream commit 45b754ae5b82949dca2b6e74fa680313cefdc813 ]

This patch checks the function parameter 'bytes' before doing the
subtraction to prevent memory corruption.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/1612282865-21846-1-git-send-email-christian.gromm@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/staging/most/aim-sound/sound.c b/drivers/staging/most/aim-sound/sound.c
index 9c645801cff4d..532ec0f7100eb 100644
--- a/drivers/staging/most/aim-sound/sound.c
+++ b/drivers/staging/most/aim-sound/sound.c
@@ -92,6 +92,8 @@ static void swap_copy24(u8 *dest, const u8 *source, unsigned int bytes)
 {
 	unsigned int i = 0;
 
+	if (bytes < 2)
+		return;
 	while (i < bytes - 2) {
 		dest[i] = source[i + 2];
 		dest[i + 1] = source[i + 1];