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From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, "Jann Horn" <jannh@google.com>,
        "Takashi Iwai" <tiwai@suse.de>, "Willy Tarreau" <w@1wt.eu>
Date:   Sun, 09 Dec 2018 21:50:33 +0000
Message-ID: <lsq.1544392233.328174599@decadent.org.uk>
Subject: [PATCH 3.16 228/328] ALSA: emu10k1: fix possible info leak to
 userspace on SNDRV_EMU10K1_IOCTL_INFO
In-Reply-To: <lsq.1544392232.713909046@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
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3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

------------------

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);