This is a note to let you know that I've just added the patch titled tun: Fix csum_start with VLAN acceleration to the 3.14-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: tun-fix-csum_start-with-vlan-acceleration.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd Mon Sep 17 00:00:00 2001 From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Date: Mon, 3 Nov 2014 04:30:13 +0800 Subject: tun: Fix csum_start with VLAN acceleration From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> commit a8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd upstream. When VLAN acceleration is in use on the xmit path, we end up setting csum_start to the wrong place. The result is that the whoever ends up doing the checksum setting will corrupt the packet instead of writing the checksum to the expected location, usually this means writing the checksum with an offset of -4. This patch fixes this by adjusting csum_start when VLAN acceleration is detected. Fixes: 6680ec68eff4 ("tuntap: hardware vlan tx support") Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/tun.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1226,6 +1226,10 @@ static ssize_t tun_put_user(struct tun_s struct tun_pi pi = { 0, skb->protocol }; ssize_t total = 0; int vlan_offset = 0, copied; + int vlan_hlen = 0; + + if (vlan_tx_tag_present(skb)) + vlan_hlen = VLAN_HLEN; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) < 0) @@ -1277,7 +1281,8 @@ static ssize_t tun_put_user(struct tun_s if (skb->ip_summed == CHECKSUM_PARTIAL) { gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; - gso.csum_start = skb_checksum_start_offset(skb); + gso.csum_start = skb_checksum_start_offset(skb) + + vlan_hlen; gso.csum_offset = skb->csum_offset; } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; @@ -1290,10 +1295,9 @@ static ssize_t tun_put_user(struct tun_s } copied = total; - total += skb->len; - if (!vlan_tx_tag_present(skb)) { - len = min_t(int, skb->len, len); - } else { + len = min_t(int, skb->len + vlan_hlen, len); + total += skb->len + vlan_hlen; + if (vlan_hlen) { int copy, ret; struct { __be16 h_vlan_proto; @@ -1304,8 +1308,6 @@ static ssize_t tun_put_user(struct tun_s veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); - len = min_t(int, skb->len + VLAN_HLEN, len); - total += VLAN_HLEN; copy = min_t(int, vlan_offset, len); ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); Patches currently in stable-queue which might be from herbert@xxxxxxxxxxxxxxxxxxx are queue-3.14/hwrng-pseries-port-to-new-read-api-and-fix-stack-corruption.patch queue-3.14/crypto-caam-fix-missing-dma-unmap-on-error-path.patch queue-3.14/tun-fix-csum_start-with-vlan-acceleration.patch queue-3.14/crypto-caam-remove-duplicated-sg-copy-functions.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html