ALSA: hda: Fix krealloc() with __GFP_ZERO usage

commit 33baefe5e72f17a6df378e48196cd8cada11deec upstream.

krealloc() doesn't work always properly with __GFP_ZERO flag as
expected.  For clearing the reallocated area, we need to clear
explicitly instead.

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 68bea67c3ca3d50c1db1cac4724a118f624318ba..22b7038cff0d17a34383b82616a866e9fc3f971b 100644 (file)
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -5793,13 +5793,15 @@ void *snd_array_new(struct snd_array *array)
                return NULL;
        if (array->used >= array->alloced) {
                int num = array->alloced + array->alloc_align;
+               int oldsize = array->alloced * array->elem_size;
                int size = (num + 1) * array->elem_size;
                void *nlist;
                if (snd_BUG_ON(num >= 4096))
                        return NULL;
-               nlist = krealloc(array->list, size, GFP_KERNEL | __GFP_ZERO);
+               nlist = krealloc(array->list, size, GFP_KERNEL);
                if (!nlist)
                        return NULL;
+               memset(nlist + oldsize, 0, size - oldsize);
                array->list = nlist;
                array->alloced = num;
        }