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authorBen Hutchings <ben.hutchings@codethink.co.uk>2018-08-15 23:44:25 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-05 14:27:06 +0300
commit7e10f14ebface44a48275c8d6dc1caae3668d5a9 (patch)
treea6d69dbcdb3c191be3bb6017a90a01ff2584ab75 /drivers/usb/misc/yurex.c
parent222471f7640d9771a993218d825d84825adc805d (diff)
downloadlinux-7e10f14ebface44a48275c8d6dc1caae3668d5a9.tar.xz
USB: yurex: Fix buffer over-read in yurex_write()
If the written data starts with a digit, yurex_write() tries to parse it as an integer using simple_strtoull(). This requires a null- terminator, and currently there's no guarantee that there is one. (The sample program at https://github.com/NeoCat/YUREX-driver-for-Linux/blob/master/sample/yurex_clock.pl writes an integer without a null terminator. It seems like it must have worked by chance!) Always add a null byte after the written data. Enlarge the buffer to allow for this. Cc: stable@vger.kernel.org Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/misc/yurex.c')
-rw-r--r--drivers/usb/misc/yurex.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 3be40eaa1ac9..1232dd49556d 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -421,13 +421,13 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
{
struct usb_yurex *dev;
int i, set = 0, retval = 0;
- char buffer[16];
+ char buffer[16 + 1];
char *data = buffer;
unsigned long long c, c2 = 0;
signed long timeout = 0;
DEFINE_WAIT(wait);
- count = min(sizeof(buffer), count);
+ count = min(sizeof(buffer) - 1, count);
dev = file->private_data;
/* verify that we actually have some data to write */
@@ -446,6 +446,7 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer,
retval = -EFAULT;
goto error;
}
+ buffer[count] = 0;
memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
switch (buffer[0]) {