From ba470f7c0e9f4a71a915a48392e69f56ce7edbf9 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 2 Jun 2015 15:20:25 +0300 Subject: [PATCH] staging: ozwpan: prevent a couple of underflows The underflow in OZ_DATA_F_ISOC_FIXED seems not harmful, but this patch is a clean up and makes my static checker a bit happier. The underflow in OZ_VENDOR_CLASS_RSP seems like it could result in memory corruption. Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- drivers/staging/ozwpan/ozusbsvc1.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/staging/ozwpan/ozusbsvc1.c b/drivers/staging/ozwpan/ozusbsvc1.c index f660bb198c65..301fee8625ed 100644 --- a/drivers/staging/ozwpan/ozusbsvc1.c +++ b/drivers/staging/ozwpan/ozusbsvc1.c @@ -342,12 +342,16 @@ static void oz_usb_handle_ep_data(struct oz_usb_ctx *usb_ctx, case OZ_DATA_F_ISOC_FIXED: { struct oz_isoc_fixed *body = (struct oz_isoc_fixed *)data_hdr; - int data_len = len-sizeof(struct oz_isoc_fixed)+1; + int data_len; int unit_size = body->unit_size; u8 *data = body->data; int count; int i; + if (len < sizeof(struct oz_isoc_fixed) - 1) + break; + data_len = len - (sizeof(struct oz_isoc_fixed) - 1); + if (!unit_size) break; count = data_len/unit_size; @@ -427,6 +431,11 @@ void oz_usb_rx(struct oz_pd *pd, struct oz_elt *elt) case OZ_VENDOR_CLASS_RSP: { struct oz_vendor_class_rsp *body = (struct oz_vendor_class_rsp *)usb_hdr; + + if (elt->length < + sizeof(struct oz_vendor_class_rsp) - 1) + break; + oz_hcd_control_cnf(usb_ctx->hport, body->req_id, body->rcode, body->data, elt->length- sizeof(struct oz_vendor_class_rsp)+1); -- 2.20.1