| From b348d7dddb6c4fbfc810b7a0626e8ec9e29f7cbb Mon Sep 17 00:00:00 2001 |
| From: Ignat Korchagin <ignat.korchagin@gmail.com> |
| Date: Thu, 17 Mar 2016 18:00:29 +0000 |
| Subject: USB: usbip: fix potential out-of-bounds write |
| |
| From: Ignat Korchagin <ignat.korchagin@gmail.com> |
| |
| 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@gmail.com> |
| Cc: Sasha Levin <sasha.levin@oracle.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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 |
| @@ -785,6 +785,17 @@ 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); |