lkml.org 
[lkml]   [2015]   [Apr]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read
Date
A string written by the user may not be zero terminated.

sscanf may read memory beyond the buffer if no zero byte
is found.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
---
drivers/usb/chipidea/debug.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c
index dfb05ed..ef08af3 100644
--- a/drivers/usb/chipidea/debug.c
+++ b/drivers/usb/chipidea/debug.c
@@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf,
char buf[32];
int ret;

- if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+ count = min_t(size_t, sizeof(buf) - 1, count);
+ if (copy_from_user(buf, ubuf, count))
return -EFAULT;

+ /* sscanf requires a zero terminated string */
+ buf[count] = 0;
+
if (sscanf(buf, "%u", &mode) != 1)
return -EINVAL;

--
2.1.4


\
 
 \ /
  Last update: 2015-04-17 08:21    [W:0.062 / U:0.076 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site