Skip to content
Permalink
Browse files Browse the repository at this point in the history
USB: usbip: fix potential out-of-bounds write
Fix potential out-of-bounds write to urb->transfer_buffer
usbip handles network communication directly in the kernel. When receiving a
packet from its peer, usbip code parses headers according to protocol. As
part of this parsing urb->actual_length is filled. Since the input for
urb->actual_length comes from the network, it should be treated as untrusted.
Any entity controlling the network may put any value in the input and the
preallocated urb->transfer_buffer may not be large enough to hold the data.
Thus, the malicious entity is able to write arbitrary data to kernel memory.

Signed-off-by: Ignat Korchagin <ignat.korchagin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
ignatk authored and gregkh committed Mar 31, 2016
1 parent 8ef34aa commit b348d7d
Showing 1 changed file with 11 additions and 0 deletions.
11 changes: 11 additions & 0 deletions drivers/usb/usbip/usbip_common.c
Expand Up @@ -741,6 +741,17 @@ int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
if (!(size > 0))
return 0;

if (size > urb->transfer_buffer_length) {
/* should not happen, probably malicious packet */
if (ud->side == USBIP_STUB) {
usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
return 0;
} else {
usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
return -EPIPE;
}
}

ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
if (ret != size) {
dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
Expand Down

0 comments on commit b348d7d

Please sign in to comment.