ALSA: rawmidi: Initialize allocated buffers

commit 5a7b44a8df822e0667fc76ed7130252523993bda upstream.

syzbot reported the uninitialized value exposure in certain situations
using virmidi loop.  It's likely a very small race at writing and
reading, and the influence is almost negligible.  But it's safer to
paper over this just by replacing the existing kvmalloc() with
kvzalloc().

Reported-by: syzbot+194dffdb8b22fc5d207a@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Takashi Iwai 2018-09-03 15:16:43 +02:00 committed by Greg Kroah-Hartman
parent 4971520cd7
commit e8e3fcbc66

View File

@ -125,7 +125,7 @@ static int snd_rawmidi_runtime_create(struct snd_rawmidi_substream *substream)
runtime->avail = 0;
else
runtime->avail = runtime->buffer_size;
if ((runtime->buffer = kmalloc(runtime->buffer_size, GFP_KERNEL)) == NULL) {
if ((runtime->buffer = kzalloc(runtime->buffer_size, GFP_KERNEL)) == NULL) {
kfree(runtime);
return -ENOMEM;
}
@ -650,7 +650,7 @@ int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
return -EINVAL;
}
if (params->buffer_size != runtime->buffer_size) {
newbuf = kmalloc(params->buffer_size, GFP_KERNEL);
newbuf = kzalloc(params->buffer_size, GFP_KERNEL);
if (!newbuf)
return -ENOMEM;
spin_lock_irq(&runtime->lock);