This is a note to let you know that I've just added the patch titled
ALSA: core: Fix unexpected error at replacing user TLV
to the 3.18-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-core-fix-unexpected-error-at-replacing-user-tlv.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 88c54cdf61f508ebcf8da2d819f5dfc03e954d1d Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Tue, 22 Aug 2017 08:15:13 +0200
Subject: ALSA: core: Fix unexpected error at replacing user TLV
From: Takashi Iwai <tiwai@xxxxxxx>
commit 88c54cdf61f508ebcf8da2d819f5dfc03e954d1d upstream.
When user tries to replace the user-defined control TLV, the kernel
checks the change of its content via memcmp(). The problem is that
the kernel passes the return value from memcmp() as is. memcmp()
gives a non-zero negative value depending on the comparison result,
and this shall be recognized as an error code.
The patch covers that corner-case, return 1 properly for the changed
TLV.
Fixes: 8aa9b586e420 ("[ALSA] Control API - more robust TLV implementation")
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/core/control.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1087,7 +1087,7 @@ static int snd_ctl_elem_user_tlv(struct
mutex_lock(&ue->card->user_ctl_lock);
change = ue->tlv_data_size != size;
if (!change)
- change = memcmp(ue->tlv_data, new_data, size);
+ change = memcmp(ue->tlv_data, new_data, size) != 0;
kfree(ue->tlv_data);
ue->tlv_data = new_data;
ue->tlv_data_size = size;
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-3.18/alsa-hda-add-stereo-mic-quirk-for-lenovo-g50-70-17aa-3978.patch
queue-3.18/alsa-core-fix-unexpected-error-at-replacing-user-tlv.patch