From: Eric Dumazet <edumazet@xxxxxxxxxx>
commit 6bc6895bdd6744e0136eaa4a11fbdb20a7db4e40 upstream.
We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: James Hughes <james.hughes@xxxxxxxxxxxxxxx>
Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
- This was applied upstream in v4.11
- Should be applied to stable v4.9.y
---
drivers/net/usb/ch9200.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c
index 8a40202c0a17..c4f1c363e24b 100644
--- a/drivers/net/usb/ch9200.c
+++ b/drivers/net/usb/ch9200.c
@@ -254,14 +254,9 @@ static struct sk_buff *ch9200_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
tx_overhead = 0x40;
len = skb->len;
- if (skb_headroom(skb) < tx_overhead) {
- struct sk_buff *skb2;
-
- skb2 = skb_copy_expand(skb, tx_overhead, 0, flags);
+ if (skb_cow_head(skb, tx_overhead)) {
dev_kfree_skb_any(skb);
- skb = skb2;
- if (!skb)
- return NULL;
+ return NULL;
}
__skb_push(skb, tx_overhead);
--
2.20.1
