The zero padding that is added to NTB's does
not zero the memory correctly.
This is because the skb_put modifies the value
of skb_out->len which results in the memset
command not setting any memory to zero as
(ctx->tx_max - skb_out->len) == 0.
I have resolved this by storing the size of
the memory to be zeroed before the skb_put
and using this in the memset call.
Signed-off-by: Jim Baxter <jim_baxter@xxxxxxxxxx>
---
drivers/net/usb/cdc_ncm.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index f317984..e2a48d7 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -1087,6 +1087,7 @@ struct sk_buff *
u16 n = 0, index, ndplen;
u8 ready2send = 0;
u32 delayed_ndp_size;
+ size_t padding_count;
/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
* accordingly. Otherwise, we should check here.
@@ -1243,11 +1244,13 @@ struct sk_buff *
* a ZLP after full sized NTBs.
*/
if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
- skb_out->len > ctx->min_tx_pkt)
- memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0,
- ctx->tx_max - skb_out->len);
- else if (skb_out->len < ctx->tx_max && (skb_out->len % dev->maxpacket) == 0)
+ skb_out->len > ctx->min_tx_pkt) {
+ padding_count = ctx->tx_max - skb_out->len;
+ memset(skb_put(skb_out, padding_count), 0, padding_count);
+ } else if (skb_out->len < ctx->tx_max &&
+ (skb_out->len % dev->maxpacket) == 0) {
*skb_put(skb_out, 1) = 0; /* force short packet */
+ }
/* set final frame length */
nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
--
1.9.1
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