staging: vt6656: vnt_tx_packet use skb_clone to preserve sk_buff.
authorMalcolm Priestley <tvboxspy@gmail.com>
Wed, 27 May 2020 08:49:18 +0000 (09:49 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 27 May 2020 10:23:10 +0000 (12:23 +0200)
The sk_buff needs to preserved for copying to various parts
of context and passing back to mac80211

clone sk_buff in context so to continue to writing to orginal
sk_buff data area to send in vnt_tx_context.

dev_kfree_skb the context on error or dev_kfree_skb the
orignal when done. The error handling continues as before.

Only one place in function needs to change from
ieee80211_get_hdrlen_from_skb to ieee80211_hdrlen(hdr) which
is already to pointing to correct position.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/b87e8cc1-f584-989d-830b-609d712f08c7@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/vt6656/rxtx.c

index a1b16ef9b27ffa939d040bcf6233eaf828e289dc..05b9a9ee0e337d61a2baef14c408247ad715000d 100644 (file)
@@ -545,13 +545,18 @@ int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
                return -ENOMEM;
        }
 
-       tx_context->skb = skb;
        tx_context->pkt_type = pkt_type;
        tx_context->frame_len = skb->len + 4;
        tx_context->tx_rate =  rate->hw_value;
 
        spin_unlock_irqrestore(&priv->lock, flags);
 
+       tx_context->skb = skb_clone(skb, GFP_ATOMIC);
+       if (!tx_context->skb) {
+               tx_context->in_use = false;
+               return -ENOMEM;
+       }
+
        tx_header_size = vnt_get_hdr_size(info);
        tx_bytes = tx_header_size + skb->len;
        tx_header_size += sizeof(struct vnt_tx_usb_header);
@@ -565,12 +570,9 @@ int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
        tx_buffer->usb.type = 0x00;
 
        tx_context->type = CONTEXT_DATA_PACKET;
-       tx_context->tx_buffer = tx_buffer;
+       tx_context->tx_buffer = skb->data;
        tx_context->buf_len = skb->len;
 
-       /* Return skb->data to mac80211 header */
-       skb_pull(skb, tx_header_size);
-
        /*Set fifo controls */
        if (pkt_type == PK_TYPE_11A)
                tx_buffer_head->fifo_ctl = 0;
@@ -606,7 +608,7 @@ int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
                tx_buffer_head->fifo_ctl |= cpu_to_le16(FIFOCTL_LHEAD);
 
        tx_buffer_head->frag_ctl =
-                       cpu_to_le16(ieee80211_get_hdrlen_from_skb(skb) << 10);
+                       cpu_to_le16(ieee80211_hdrlen(hdr->frame_control) << 10);
 
        if (info->control.hw_key)
                tx_context->frame_len += info->control.hw_key->icv_len;
@@ -623,10 +625,13 @@ int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
        spin_lock_irqsave(&priv->lock, flags);
 
        if (vnt_tx_context(priv, tx_context)) {
+               dev_kfree_skb(tx_context->skb);
                spin_unlock_irqrestore(&priv->lock, flags);
                return -EIO;
        }
 
+       dev_kfree_skb(skb);
+
        spin_unlock_irqrestore(&priv->lock, flags);
 
        return 0;