From: Johan Hovold <johan@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 654b404f2a222f918af9b0cd18ad469d0c941a8e upstream.
Add missing sanity check to the bulk-in completion handler to avoid an
integer underflow that can be triggered by a malicious device.
This avoids leaking 128 kB of memory content from after the URB transfer
buffer to user space.
Fixes: 8c209e6782ca ("USB: make actual_length in struct urb field u32")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/usb/serial/io_ti.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 2e4589a7b982..e527a2780855 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -1658,7 +1658,7 @@ static void edge_bulk_in_callback(struct urb *urb)
port_number = edge_port->port->port_number;
- if (edge_port->lsr_event) {
+ if (urb->actual_length > 0 && edge_port->lsr_event) {
edge_port->lsr_event = 0;
dev_dbg(dev, "%s ===== Port %u LSR Status = %02x, Data = %02x ======\n",
__func__, port_number, edge_port->lsr_mask, *data);
--
2.12.2