USB: serial: io_ti: fix information leak in completion handler

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: 8c209e6782 ("USB: make actual_length in struct urb field u32")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>	# 2.6.30
Signed-off-by: Johan Hovold <johan@kernel.org>
This commit is contained in:
Johan Hovold 2017-03-06 17:36:40 +01:00
parent 367ec17067
commit 654b404f2a
1 changed files with 1 additions and 1 deletions

View File

@ -1761,7 +1761,7 @@ 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);