This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Fix unintentional sign extension issue
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usb-audio-fix-unintentional-sign-extension-issue.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 50b1affc891cbc103a2334ce909a026e25f4c84d Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Date: Thu, 18 Mar 2021 13:20:08 +0000
Subject: ALSA: usb-audio: Fix unintentional sign extension issue
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
commit 50b1affc891cbc103a2334ce909a026e25f4c84d upstream.
The shifting of the u8 integer device by 24 bits to the left will
be promoted to a 32 bit signed int and then sign-extended to a
64 bit unsigned long. In the event that the top bit of device is
set then all then all the upper 32 bits of the unsigned long will
end up as also being set because of the sign-extension. Fix this
by casting device to an unsigned long before the shift.
Addresses-Coverity: ("Unintended sign extension")
Fixes: a07df82c7990 ("ALSA: usb-audio: Add DJM750 to Pioneer mixer quirk")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210318132008.15266-1-colin.king@xxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -2883,7 +2883,7 @@ static int snd_djm_controls_put(struct s
u8 group = (private_value & SND_DJM_GROUP_MASK) >> SND_DJM_GROUP_SHIFT;
u16 value = elem->value.enumerated.item[0];
- kctl->private_value = ((device << SND_DJM_DEVICE_SHIFT) |
+ kctl->private_value = (((unsigned long)device << SND_DJM_DEVICE_SHIFT) |
(group << SND_DJM_GROUP_SHIFT) |
value);
@@ -2921,7 +2921,7 @@ static int snd_djm_controls_create(struc
value = device->controls[i].default_value;
knew.name = device->controls[i].name;
knew.private_value = (
- (device_idx << SND_DJM_DEVICE_SHIFT) |
+ ((unsigned long)device_idx << SND_DJM_DEVICE_SHIFT) |
(i << SND_DJM_GROUP_SHIFT) |
value);
err = snd_djm_controls_update(mixer, device_idx, i, value);
Patches currently in stable-queue which might be from colin.king@xxxxxxxxxxxxx are
queue-5.11/alsa-usb-audio-fix-unintentional-sign-extension-issue.patch
