From c4fd43793bdecb986bfc80e00c8792556c3f1c7f Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 14 Sep 2017 02:01:16 +0300
Subject: [PATCH] ALSA: hwdep: prevent a harmless shift wrapping bug
Git-commit: c4fd43793bdecb986bfc80e00c8792556c3f1c7f
Patch-mainline: v4.15-rc1
References: bsc#1121278
The "info.index" variable represents a bit in hw->dsp_loaded which is
an unsigned int. If it's higher than 31 we hit a shift wrapping bug.
This seems harmless, but I wanted to silence the static checker warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/core/hwdep.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/core/hwdep.c b/sound/core/hwdep.c
index a73baa1242be..8faae3d1455d 100644
--- a/sound/core/hwdep.c
+++ b/sound/core/hwdep.c
@@ -228,6 +228,8 @@ static int snd_hwdep_dsp_load(struct snd_hwdep *hw,
memset(&info, 0, sizeof(info));
if (copy_from_user(&info, _info, sizeof(info)))
return -EFAULT;
+ if (info.index >= 32)
+ return -EINVAL;
/* check whether the dsp was already loaded */
if (hw->dsp_loaded & (1 << info.index))
return -EBUSY;
--
2.20.1