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authorIgnat Korchagin <ignat.korchagin@gmail.com>2016-03-17 18:00:29 +0000
committerSasha Levin <sasha.levin@oracle.com>2016-07-12 08:47:50 -0400
commit9a71843e3ab0f1ffb766c4074f761ba57e3c12c8 (patch)
tree067bd674bdb69ddb313f05f2f44792cc625b20b7
parentb42ffd9cc12d324180d3b9063df06fc786250efa (diff)
USB: usbip: fix potential out-of-bounds write
[ Upstream commit b348d7dddb6c4fbfc810b7a0626e8ec9e29f7cbb ] 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> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
-rw-r--r--drivers/usb/usbip/usbip_common.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c
index facaaf003f19..e40da7759a0e 100644
--- a/drivers/usb/usbip/usbip_common.c
+++ b/drivers/usb/usbip/usbip_common.c
@@ -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);