Commit aeca3a77 authored by Jim Baxter's avatar Jim Baxter Committed by David S. Miller

net: cdc_ncm: Fix TX zero padding

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: default avatarJim Baxter <jim_baxter@mentor.com>
Reviewed-by: default avatarBjørn Mork <bjorn@mork.no>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b210aeae
...@@ -1088,6 +1088,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) ...@@ -1088,6 +1088,7 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
u16 n = 0, index, ndplen; u16 n = 0, index, ndplen;
u8 ready2send = 0; u8 ready2send = 0;
u32 delayed_ndp_size; u32 delayed_ndp_size;
size_t padding_count;
/* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated /* When our NDP gets written in cdc_ncm_ndp(), then skb_out->len gets updated
* accordingly. Otherwise, we should check here. * accordingly. Otherwise, we should check here.
...@@ -1244,11 +1245,13 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) ...@@ -1244,11 +1245,13 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign)
* a ZLP after full sized NTBs. * a ZLP after full sized NTBs.
*/ */
if (!(dev->driver_info->flags & FLAG_SEND_ZLP) && if (!(dev->driver_info->flags & FLAG_SEND_ZLP) &&
skb_out->len > ctx->min_tx_pkt) skb_out->len > ctx->min_tx_pkt) {
memset(skb_put(skb_out, ctx->tx_max - skb_out->len), 0, padding_count = ctx->tx_max - skb_out->len;
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) } else if (skb_out->len < ctx->tx_max &&
(skb_out->len % dev->maxpacket) == 0) {
*skb_put(skb_out, 1) = 0; /* force short packet */ *skb_put(skb_out, 1) = 0; /* force short packet */
}
/* set final frame length */ /* set final frame length */
nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data; nth16 = (struct usb_cdc_ncm_nth16 *)skb_out->data;
......
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