Prevent access to arbitrary memory locations in gen_ndis_set_resp via manipulation of buf->InformationBufferOffset. Lack of validation of BufOffset could be exploited to dump arbitrary memory contents via NDIS packet filter.
Signed-off-by: Szymon Heidrich szymon.heidrich@gmail.com --- drivers/usb/gadget/rndis.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/rndis.c b/drivers/usb/gadget/rndis.c index 13c327ea38..3948f2cc9a 100644 --- a/drivers/usb/gadget/rndis.c +++ b/drivers/usb/gadget/rndis.c @@ -855,14 +855,17 @@ static int rndis_set_response(int configNr, rndis_set_msg_type *buf) rndis_set_cmplt_type *resp; rndis_resp_t *r;
+ BufLength = get_unaligned_le32(&buf->InformationBufferLength); + BufOffset = get_unaligned_le32(&buf->InformationBufferOffset); + if ((BufOffset > RNDIS_MAX_TOTAL_SIZE - 8) || + (BufLength > RNDIS_MAX_TOTAL_SIZE - 8 - BufOffset)) + return -EINVAL; + r = rndis_add_response(configNr, sizeof(rndis_set_cmplt_type)); if (!r) return -ENOMEM; resp = (rndis_set_cmplt_type *) r->buf;
- BufLength = get_unaligned_le32(&buf->InformationBufferLength); - BufOffset = get_unaligned_le32(&buf->InformationBufferOffset); - #ifdef VERBOSE debug("%s: Length: %d\n", __func__, BufLength); debug("%s: Offset: %d\n", __func__, BufOffset);