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authorTakashi Iwai <tiwai@suse.de>2017-08-22 08:15:13 +0200
committerTakashi Iwai <tiwai@suse.de>2017-08-22 15:43:40 +0200
commit88c54cdf61f508ebcf8da2d819f5dfc03e954d1d (patch)
treeef895c90efc68011841b0bbecc011b8fceb8926c
parent07b3b5e9ed807a0d2077319b8e43a42e941db818 (diff)
downloadlinux-88c54cdf61f508ebcf8da2d819f5dfc03e954d1d.tar.bz2
ALSA: core: Fix unexpected error at replacing user TLV
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") Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/core/control.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/core/control.c b/sound/core/control.c
index 3c6be1452e35..4525e127afd9 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1137,7 +1137,7 @@ static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol,
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;