From: Slawomir Laba <slawomirx.laba@xxxxxxxxx> [ Upstream commit 92c6058024e87087cf1b99b0389d67c0a886360e ] When a packet contains an IPv6 header with next header which is an extension header and not a protocol one, the kernel function skb_transport_header called with such sk_buff will return a pointer to the extension header and not to the TCP one. The above explained call caused a problem with packet processing for skb with encapsulation for tunnel with I40E_TX_CTX_EXT_IP_IPV6. The extension header was not skipped at all. The ipv6_skip_exthdr function does check if next header of the IPV6 header is an extension header and doesn't modify the l4_proto pointer if it points to a protocol header value so its safe to omit the comparison of exthdr and l4.hdr pointers. The ipv6_skip_exthdr can return value -1. This means that the skipping process failed and there is something wrong with the packet so it will be dropped. Fixes: a3fd9d8876a5 ("i40e/i40evf: Handle IPv6 extension headers in checksum offload") Signed-off-by: Slawomir Laba <slawomirx.laba@xxxxxxxxx> Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@xxxxxxxxx> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@xxxxxxxxx> Tested-by: Tony Brelinski <tonyx.brelinski@xxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 3f5825fa67c99..38dec49ac64d2 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -3102,13 +3102,16 @@ static int i40e_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags, l4_proto = ip.v4->protocol; } else if (*tx_flags & I40E_TX_FLAGS_IPV6) { + int ret; + tunnel |= I40E_TX_CTX_EXT_IP_IPV6; exthdr = ip.hdr + sizeof(*ip.v6); l4_proto = ip.v6->nexthdr; - if (l4.hdr != exthdr) - ipv6_skip_exthdr(skb, exthdr - skb->data, - &l4_proto, &frag_off); + ret = ipv6_skip_exthdr(skb, exthdr - skb->data, + &l4_proto, &frag_off); + if (ret < 0) + return -1; } /* define outer transport */ -- 2.27.0