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path: root/drivers/net/usb/ax88179_178a.c
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Diffstat (limited to 'drivers/net/usb/ax88179_178a.c')
-rw-r--r--drivers/net/usb/ax88179_178a.c68
1 files changed, 39 insertions, 29 deletions
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 1a627ba4b850..a31098981a65 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1468,58 +1468,68 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
u16 hdr_off;
u32 *pkt_hdr;
- /* This check is no longer done by usbnet */
- if (skb->len < dev->net->hard_header_len)
+ /* At the end of the SKB, there's a header telling us how many packets
+ * are bundled into this buffer and where we can find an array of
+ * per-packet metadata (which contains elements encoded into u16).
+ */
+ if (skb->len < 4)
return 0;
-
skb_trim(skb, skb->len - 4);
rx_hdr = get_unaligned_le32(skb_tail_pointer(skb));
-
pkt_cnt = (u16)rx_hdr;
hdr_off = (u16)(rx_hdr >> 16);
+
+ if (pkt_cnt == 0)
+ return 0;
+
+ /* Make sure that the bounds of the metadata array are inside the SKB
+ * (and in front of the counter at the end).
+ */
+ if (pkt_cnt * 2 + hdr_off > skb->len)
+ return 0;
pkt_hdr = (u32 *)(skb->data + hdr_off);
- while (pkt_cnt--) {
+ /* Packets must not overlap the metadata array */
+ skb_trim(skb, hdr_off);
+
+ for (; ; pkt_cnt--, pkt_hdr++) {
u16 pkt_len;
le32_to_cpus(pkt_hdr);
pkt_len = (*pkt_hdr >> 16) & 0x1fff;
- /* Check CRC or runt packet */
- if ((*pkt_hdr & AX_RXHDR_CRC_ERR) ||
- (*pkt_hdr & AX_RXHDR_DROP_ERR)) {
- skb_pull(skb, (pkt_len + 7) & 0xFFF8);
- pkt_hdr++;
- continue;
- }
-
- if (pkt_cnt == 0) {
- skb->len = pkt_len;
- /* Skip IP alignment pseudo header */
- skb_pull(skb, 2);
- skb_set_tail_pointer(skb, skb->len);
- skb->truesize = pkt_len + sizeof(struct sk_buff);
- ax88179_rx_checksum(skb, pkt_hdr);
- return 1;
- }
+ if (pkt_len > skb->len)
+ return 0;
- ax_skb = skb_clone(skb, GFP_ATOMIC);
- if (ax_skb) {
+ /* Check CRC or runt packet */
+ if (((*pkt_hdr & (AX_RXHDR_CRC_ERR | AX_RXHDR_DROP_ERR)) == 0) &&
+ pkt_len >= 2 + ETH_HLEN) {
+ bool last = (pkt_cnt == 0);
+
+ if (last) {
+ ax_skb = skb;
+ } else {
+ ax_skb = skb_clone(skb, GFP_ATOMIC);
+ if (!ax_skb)
+ return 0;
+ }
ax_skb->len = pkt_len;
/* Skip IP alignment pseudo header */
skb_pull(ax_skb, 2);
skb_set_tail_pointer(ax_skb, ax_skb->len);
ax_skb->truesize = pkt_len + sizeof(struct sk_buff);
ax88179_rx_checksum(ax_skb, pkt_hdr);
+
+ if (last)
+ return 1;
+
usbnet_skb_return(dev, ax_skb);
- } else {
- return 0;
}
- skb_pull(skb, (pkt_len + 7) & 0xFFF8);
- pkt_hdr++;
+ /* Trim this packet away from the SKB */
+ if (!skb_pull(skb, (pkt_len + 7) & 0xFFF8))
+ return 0;
}
- return 1;
}
static struct sk_buff *