[PATCH 3.16 228/328] ALSA: emu10k1: fix possible info leak to userspace on SNDRV_EMU10K1_IOCTL_INFO

Ben Hutchings
2018-12-09T22:22:55Z

From: Willy Tarreau <w@1wt.eu>

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
sound/pci/emu10k1/emufx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/sound/pci/emu10k1/emufx.c
+++ b/sound/pci/emu10k1/emufx.c
@@ -2521,7 +2521,7 @@ static int snd_emu10k1_fx8010_ioctl(stru
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);