4.4-stable review patch. If anyone has any objections, please let me know.
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From: zhangliping zhangliping02@baidu.com
[ Upstream commit 67c8d22a73128ff910e2287567132530abcf5b71 ]
If we want to add a datapath flow, which has more than 500 vxlan outputs' action, we will get the following error reports: openvswitch: netlink: Flow action size 32832 bytes exceeds max openvswitch: netlink: Flow action size 32832 bytes exceeds max openvswitch: netlink: Actions may not be safe on all matching packets ... ...
It seems that we can simply enlarge the MAX_ACTIONS_BUFSIZE to fix it, but this is not the root cause. For example, for a vxlan output action, we need about 60 bytes for the nlattr, but after it is converted to the flow action, it only occupies 24 bytes. This means that we can still support more than 1000 vxlan output actions for a single datapath flow under the the current 32k max limitation.
So even if the nla_len(attr) is larger than MAX_ACTIONS_BUFSIZE, we shouldn't report EINVAL and keep it move on, as the judgement can be done by the reserve_sfa_size.
Signed-off-by: zhangliping zhangliping02@baidu.com Acked-by: Pravin B Shelar pshelar@ovn.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/openvswitch/flow_netlink.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
--- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -1672,14 +1672,11 @@ int ovs_nla_put_mask(const struct sw_flo
#define MAX_ACTIONS_BUFSIZE (32 * 1024)
-static struct sw_flow_actions *nla_alloc_flow_actions(int size, bool log) +static struct sw_flow_actions *nla_alloc_flow_actions(int size) { struct sw_flow_actions *sfa;
- if (size > MAX_ACTIONS_BUFSIZE) { - OVS_NLERR(log, "Flow action size %u bytes exceeds max", size); - return ERR_PTR(-EINVAL); - } + WARN_ON_ONCE(size > MAX_ACTIONS_BUFSIZE);
sfa = kmalloc(sizeof(*sfa) + size, GFP_KERNEL); if (!sfa) @@ -1752,12 +1749,15 @@ static struct nlattr *reserve_sfa_size(s new_acts_size = ksize(*sfa) * 2;
if (new_acts_size > MAX_ACTIONS_BUFSIZE) { - if ((MAX_ACTIONS_BUFSIZE - next_offset) < req_size) + if ((MAX_ACTIONS_BUFSIZE - next_offset) < req_size) { + OVS_NLERR(log, "Flow action size exceeds max %u", + MAX_ACTIONS_BUFSIZE); return ERR_PTR(-EMSGSIZE); + } new_acts_size = MAX_ACTIONS_BUFSIZE; }
- acts = nla_alloc_flow_actions(new_acts_size, log); + acts = nla_alloc_flow_actions(new_acts_size); if (IS_ERR(acts)) return (void *)acts;
@@ -2369,7 +2369,7 @@ int ovs_nla_copy_actions(struct net *net { int err;
- *sfa = nla_alloc_flow_actions(nla_len(attr), log); + *sfa = nla_alloc_flow_actions(min(nla_len(attr), MAX_ACTIONS_BUFSIZE)); if (IS_ERR(*sfa)) return PTR_ERR(*sfa);