[PATCH 5.1 62/96] ALSA: usb-audio: fix sign unintended sign extension on left shifts

Greg Kroah-Hartman
2019-07-08T15:33:27Z

From: Colin Ian King <colin.king@canonical.com>

commit 2acf5a3e6e9371e63c9e4ff54d84d08f630467a0 upstream.

There are a couple of left shifts of unsigned 8 bit values that
first get promoted to signed ints and hence get sign extended
on the shift if the top bit of the 8 bit values are set. Fix
this by casting the 8 bit values to unsigned ints to stop the
unintentional sign extension.

Addresses-Coverity: ("Unintended sign extension")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/usb/mixer_quirks.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -754,7 +754,7 @@ static int snd_ni_control_init_val(struc
return err;
}

- kctl->private_value |= (value << 24);
+ kctl->private_value |= ((unsigned int)value << 24);
return 0;
}

@@ -915,7 +915,7 @@ static int snd_ftu_eff_switch_init(struc
if (err < 0)
return err;

- kctl->private_value |= value[0] << 24;
+ kctl->private_value |= (unsigned int)value[0] << 24;
return 0;
}