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author | Shmulik Ladkani <shmulik.ladkani@gmail.com> | 2016-09-29 12:10:40 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-10-03 21:40:50 -0400 |
commit | f39acc84aad10710e89835c60d3b6694c43a8dd9 (patch) | |
tree | 13b0d222768776fbff3cf1a7b2bc63ccfa851c10 /net/sched | |
parent | f814bfd765218908b23e21ca7f0b6f403fb88972 (diff) | |
download | linux-f39acc84aad10710e89835c60d3b6694c43a8dd9.tar.gz linux-f39acc84aad10710e89835c60d3b6694c43a8dd9.tar.bz2 linux-f39acc84aad10710e89835c60d3b6694c43a8dd9.zip |
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')
-rw-r--r-- | net/sched/act_vlan.c | 9 |
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) { case TCA_VLAN_ACT_POP: err = skb_vlan_pop(skb); @@ -83,6 +89,9 @@ drop: action = TC_ACT_SHOT; v->tcf_qstats.drops++; unlock: + if (skb_at_tc_ingress(skb)) + skb_pull_rcsum(skb, skb->mac_len); + spin_unlock(&v->tcf_lock); return action; } |