This is a note to let you know that I've just added the patch titled ip_gre: check packet length and mtu correctly in erspan tx to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ip_gre-check-packet-length-and-mtu-correctly-in-erspan-tx.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed Dec 20 18:17:52 CET 2017 From: William Tu <u9012063@xxxxxxxxx> Date: Thu, 5 Oct 2017 12:07:12 -0700 Subject: ip_gre: check packet length and mtu correctly in erspan tx From: William Tu <u9012063@xxxxxxxxx> [ Upstream commit f192970de860d3ab90aa9e2a22853201a57bde78 ] Similarly to early patch for erspan_xmit(), the ARPHDR_ETHER device is the length of the whole ether packet. So skb->len should subtract the dev->hard_header_len. Fixes: 1a66a836da63 ("gre: add collect_md mode to ERSPAN tunnel") Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN") Signed-off-by: William Tu <u9012063@xxxxxxxxx> Cc: Xin Long <lucien.xin@xxxxxxxxx> Cc: David Laight <David.Laight@xxxxxxxxxx> Reviewed-by: Xin Long <lucien.xin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/ip_gre.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -579,8 +579,8 @@ static void erspan_fb_xmit(struct sk_buf if (gre_handle_offloads(skb, false)) goto err_free_rt; - if (skb->len > dev->mtu) { - pskb_trim(skb, dev->mtu); + if (skb->len > dev->mtu + dev->hard_header_len) { + pskb_trim(skb, dev->mtu + dev->hard_header_len); truncate = true; } @@ -731,8 +731,8 @@ static netdev_tx_t erspan_xmit(struct sk if (skb_cow_head(skb, dev->needed_headroom)) goto free_skb; - if (skb->len - dev->hard_header_len > dev->mtu) { - pskb_trim(skb, dev->mtu); + if (skb->len > dev->mtu + dev->hard_header_len) { + pskb_trim(skb, dev->mtu + dev->hard_header_len); truncate = true; } Patches currently in stable-queue which might be from u9012063@xxxxxxxxx are queue-4.14/ip_gre-check-packet-length-and-mtu-correctly-in-erspan-tx.patch