path: root/net/sched/act_vlan.c
diff options
authorShmulik Ladkani <shmulik.ladkani@gmail.com>2016-09-29 12:10:40 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-03 21:40:50 -0400
commitf39acc84aad10710e89835c60d3b6694c43a8dd9 (patch)
tree13b0d222768776fbff3cf1a7b2bc63ccfa851c10 /net/sched/act_vlan.c
parentnet: mvmdio: do not clk_disable_unprepare() NULL clock (diff)
net/sched: act_vlan: Push skb->data to mac_header prior calling skb_vlan_*() functions
Generic skb_vlan_push/skb_vlan_pop functions don't properly handle the case where the input skb data pointer does not point at the mac header: - They're doing push/pop, but fail to properly unwind data back to its original location. For example, in the skb_vlan_push case, any subsequent 'skb_push(skb, skb->mac_len)' calls make the skb->data point 4 bytes BEFORE start of frame, leading to bogus frames that may be transmitted. - They update rcsum per the added/removed 4 bytes tag. Alas if data is originally after the vlan/eth headers, then these bytes were already pulled out of the csum. OTOH calling skb_vlan_push/skb_vlan_pop with skb->data at mac_header present no issues. act_vlan is the only caller to skb_vlan_*() that has skb->data pointing at network header (upon ingress). Other calles (ovs, bpf) already adjust skb->data at mac_header. This patch fixes act_vlan to point to the mac_header prior calling skb_vlan_*() functions, as other callers do. Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Pravin Shelar <pshelar@ovn.org> Cc: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/act_vlan.c')
1 files changed, 9 insertions, 0 deletions
diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
index a95c00b119da..b57fcbcefea1 100644
--- a/net/sched/act_vlan.c
+++ b/net/sched/act_vlan.c
@@ -37,6 +37,12 @@ static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
bstats_update(&v->tcf_bstats, skb);
action = v->tcf_action;
+ /* Ensure 'data' points at mac_header prior calling vlan manipulating
+ * functions.
+ */
+ if (skb_at_tc_ingress(skb))
+ skb_push_rcsum(skb, skb->mac_len);
switch (v->tcfv_action) {
err = skb_vlan_pop(skb);
@@ -83,6 +89,9 @@ drop:
action = TC_ACT_SHOT;
+ if (skb_at_tc_ingress(skb))
+ skb_pull_rcsum(skb, skb->mac_len);
return action;