4.9-stable review patch. If anyone has any objections, please let me know.
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From: 배석진 soukjin.bae@samsung.com
[ Upstream commit 62230715fd2453b3ba948c9d83cfb3ada9169169 ]
Only first fragment has the sport/dport information, not the following ones.
If we want consistent hash for all fragments, we need to ignore ports even for first fragment.
This bug is visible for IPv6 traffic, if incoming fragments do not have a flow label, since skb_get_hash() will give different results for first fragment and following ones.
It is also visible if any routing rule wants dissection and sport or dport.
See commit 5e5d6fed3741 ("ipv6: route: dissect flow in input path if fib rules need it") for details.
[edumazet] rewrote the changelog completely.
Fixes: 06635a35d13d ("flow_dissect: use programable dissector in skb_flow_dissect and friends") Signed-off-by: 배석진 soukjin.bae@samsung.com Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/flow_dissector.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -538,8 +538,8 @@ ip_proto_again: break; }
- if (dissector_uses_key(flow_dissector, - FLOW_DISSECTOR_KEY_PORTS)) { + if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) && + !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) { key_ports = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_PORTS, target_container);