DivestOS/Patches/Linux_CVEs/CVE-2017-0404/ANY/0.patch
2017-10-29 22:14:37 -04:00

42 lines
1.6 KiB
Diff

From 4faa6d2e9b53546823882d8889820ff9ce3c372f Mon Sep 17 00:00:00 2001
From: Siqi Lin <siqilin@google.com>
Date: Wed, 2 Nov 2016 16:51:08 -0700
Subject: [PATCH] ALSA: info: Check for integer overflow in
snd_info_entry_write()
snd_info_entry_write() resizes the buffer with an unsigned long
size argument that gets truncated because resize_info_buffer()
takes the size parameter as an unsigned int. On 64-bit kernels,
this causes the following copy_to_user() to write out-of-bounds
if (pos + count) can't be represented by an unsigned int.
Bug: 32510733
Change-Id: I9e8b55f93f2bd606b4a73b5a4525b71ee88c7c23
Signed-off-by: Siqi Lin <siqilin@google.com>
---
sound/core/info.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/sound/core/info.c b/sound/core/info.c
index 418b4ec43cadb..a4af0ba92d30f 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -253,6 +253,7 @@ static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer
struct snd_info_buffer *buf;
ssize_t size = 0;
loff_t pos;
+ unsigned long realloc_size;
data = file->private_data;
if (snd_BUG_ON(!data))
@@ -261,7 +262,8 @@ static ssize_t snd_info_entry_write(struct file *file, const char __user *buffer
pos = *offset;
if (pos < 0 || (long) pos != pos || (ssize_t) count < 0)
return -EIO;
- if ((unsigned long) pos + (unsigned long) count < (unsigned long) pos)
+ realloc_size = (unsigned long) pos + (unsigned long) count;
+ if (realloc_size < (unsigned long) pos || realloc_size > UINT_MAX)
return -EIO;
switch (entry->content) {
case SNDRV_INFO_CONTENT_TEXT: