From: Willy Tarreau <w@1wt.eu>
Date: Sat, 8 Sep 2018 06:12:21 +0000 (+0200)
Subject: ALSA: emu10k1: fix possible info leak to userspace on SNDRV_EMU10K1_IOCTL_INFO
X-Git-Tag: v4.9.130~39
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8a47a993db8627c3bd5bde193f5f3b2b4718a765;p=platform%2Fkernel%2Flinux-amlogic.git

ALSA: emu10k1: fix possible info leak to userspace on SNDRV_EMU10K1_IOCTL_INFO

commit 49434c6c575d2008c0abbc93e615019f39e01252 upstream.

snd_emu10k1_fx8010_ioctl(SNDRV_EMU10K1_IOCTL_INFO) allocates
memory using kmalloc() and partially fills it by calling
snd_emu10k1_fx8010_info() before returning the resulting
structure to userspace, leaving uninitialized holes. Let's
just use kzalloc() here.

BugLink: http://blog.infosectcbr.com.au/2018/09/linux-kernel-infoleaks.html
Signed-off-by: Willy Tarreau <w@1wt.eu>
Cc: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c
index 56fc47bd6dba..50b216fc369f 100644
--- a/sound/pci/emu10k1/emufx.c
+++ b/sound/pci/emu10k1/emufx.c
@@ -2520,7 +2520,7 @@ static int snd_emu10k1_fx8010_ioctl(struct snd_hwdep * hw, struct file *file, un
 		emu->support_tlv = 1;
 		return put_user(SNDRV_EMU10K1_VERSION, (int __user *)argp);
 	case SNDRV_EMU10K1_IOCTL_INFO:
-		info = kmalloc(sizeof(*info), GFP_KERNEL);
+		info = kzalloc(sizeof(*info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 		snd_emu10k1_fx8010_info(emu, info);