[PATCH AUTOSEL 4.4 09/11] staging: most: sound: add sanity check for function argument

From: Sasha Levin
Date: Wed Feb 24 2021 - 09:25:45 EST


From: Christian Gromm <christian.gromm@xxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/1612282865-21846-1-git-send-email-christian.gromm@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/staging/most/aim-sound/sound.c | 2 ++
1 file changed, 2 insertions(+)

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];
--
2.27.0