[PATCH 2/2] USB: ldusb: use unsigned size format specifiers

From: Johan Hovold
Date: Tue Oct 22 2019 - 10:32:10 EST


A recent info-leak bug manifested itself along with warning about a
negative buffer overflow:

ldusb 1-1:0.28: Read buffer overflow, -131383859965943 bytes dropped

when it was really a rather large positive one.

A sanity check that prevents this has now been put in place, but let's
fix up the size format specifiers, which should all be unsigned.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/misc/ldusb.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c
index c3e764909fd0..dd1ea25e42b1 100644
--- a/drivers/usb/misc/ldusb.c
+++ b/drivers/usb/misc/ldusb.c
@@ -487,7 +487,7 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
}
bytes_to_read = min(count, *actual_buffer);
if (bytes_to_read < *actual_buffer)
- dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
+ dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n",
*actual_buffer-bytes_to_read);

/* copy one interrupt_in_buffer from ring_buffer into userspace */
@@ -562,8 +562,9 @@ static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
/* write the data into interrupt_out_buffer from userspace */
bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
if (bytes_to_write < count)
- dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write);
- dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
+ dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n",
+ count - bytes_to_write);
+ dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n",
__func__, count, bytes_to_write);

if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
--
2.23.0