On Friday, October 21, 2016 11:05:45 PM CEST Arnd Bergmann wrote:
Can you explain why "dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_VLAN) && skb_vlan_tag_present(skb)" implies
"eth_type_vlan(proto))"?
If I add uninitialized_var() here, I would at least put that in
a comment here.
Found it now myself: if skb_vlan_tag_present(skb), then we don't
access 'vlan', otherwise we know it is initialized because
eth_type_vlan(proto) has to be true.
On a related note, I also don't see how
"dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_VLAN)"
implies that skb is non-NULL. I guess this is related to the
first one.
I'm still unsure about this one.
I also found something else that is suspicious: 'vlan' points
to the local _vlan variable, but that has gone out of scope
by the time we access the pointer, which doesn't seem safe.
Arnd