3.16.35-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ignat Korchagin <ignat.korchagin@xxxxxxxxx> commit b348d7dddb6c4fbfc810b7a0626e8ec9e29f7cbb upstream. 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@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/staging/usbip/usbip_common.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/drivers/staging/usbip/usbip_common.c +++ b/drivers/staging/usbip/usbip_common.c @@ -741,6 +741,17 @@ int usbip_recv_xbuff(struct usbip_device 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); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html