net_sched: refetch skb protocol for each filter
[ Upstream commit cd0c4e70fc0ccfa705cdf55efb27519ce9337a26 ] Martin reported a set of filters don't work after changing from reclassify to continue. Looking into the code, it looks like skb protocol is not always fetched for each iteration of the filters. But, as demonstrated by Martin, TC actions could modify skb->protocol, for example act_vlan, this means we have to refetch skb protocol in each iteration, rather than using the one we fetch in the beginning of the loop. This bug is _not_ introduced by commit 3b3ae880 ("net: sched: consolidate tc_classify{,_compat}"), technically, if act_vlan is the only action that modifies skb protocol, then it is commit c7e2b968 ("sched: introduce vlan action") which introduced this bug. Reported-by: NMartin Olsson <martin.olsson+netdev@sentorsecurity.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Acked-by: NJamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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