From: Alexander Duyck <aduyck@xxxxxxxxxxxx> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit 461547f3158978c180d74484d58e82be9b8e7357, since we lack the flow dissector flags in this release we guard the flow label access using a test on 'skb' being NULL ] This patch fixes an issue with unaligned accesses when using eth_get_headlen on a page that was DMA aligned instead of being IP aligned. The fact is when trying to check the length we don't need to be looking at the flow label so we can reorder the checks to first check if we are supposed to gather the flow label and then make the call to actually get it. v2: Updated path so that either STOP_AT_FLOW_LABEL or KEY_FLOW_LABEL can cause us to check for the flow label. Reported-by: Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx> Signed-off-by: Alexander Duyck <aduyck@xxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> --- net/core/flow_dissector.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 2c35c02..f96d2ca 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -113,7 +113,6 @@ ip: case htons(ETH_P_IPV6): { const struct ipv6hdr *iph; struct ipv6hdr _iph; - __be32 flow_label; ipv6: iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); @@ -130,8 +129,9 @@ ipv6: flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr); flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); - flow_label = ip6_flowlabel(iph); - if (flow_label) { + if (skb && ip6_flowlabel(iph)) { + __be32 flow_label = ip6_flowlabel(iph); + /* Awesome, IPv6 packet has a flow label so we can * use that to represent the ports without any * further dissection. -- 2.5.0 -- 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