4.9-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings ben.hutchings@codethink.co.uk
commit 7e10f14ebface44a48275c8d6dc1caae3668d5a9 upstream.
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_cl... 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
--- drivers/usb/misc/yurex.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -431,13 +431,13 @@ static ssize_t yurex_write(struct file * { 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 */ @@ -456,6 +456,7 @@ static ssize_t yurex_write(struct file * retval = -EFAULT; goto error; } + buffer[count] = 0; memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE);
switch (buffer[0]) {