From: Eric Dumazet edumazet@google.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ Upstream commit b7c6d2675899cfff0180412c63fc9cbd5bacdb4d ]
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: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver") Signed-off-by: Eric Dumazet edumazet@google.com Cc: James Hughes james.hughes@raspberrypi.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/net/usb/smsc75xx.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c index d9e7892262fa..2c526ca29cde 100644 --- a/drivers/net/usb/smsc75xx.c +++ b/drivers/net/usb/smsc75xx.c @@ -2198,13 +2198,9 @@ static struct sk_buff *smsc75xx_tx_fixup(struct usbnet *dev, { u32 tx_cmd_a, tx_cmd_b;
- if (skb_headroom(skb) < SMSC75XX_TX_OVERHEAD) { - struct sk_buff *skb2 = - skb_copy_expand(skb, SMSC75XX_TX_OVERHEAD, 0, flags); + if (skb_cow_head(skb, SMSC75XX_TX_OVERHEAD)) { dev_kfree_skb_any(skb); - skb = skb2; - if (!skb) - return NULL; + return NULL; }
tx_cmd_a = (u32)(skb->len & TX_CMD_A_LEN) | TX_CMD_A_FCS;