gcc warns about an uninitialized pointer dereference in the vlan priority handling:
net/core/flow_dissector.c: In function '__skb_flow_dissect': net/core/flow_dissector.c:281:61: error: 'vlan' may be used uninitialized in this function [-Werror=maybe-uninitialized] >From all I can tell, this warning is about a real bug, and we should not attempt look up the vlan header if there was no vlan tag. Fixes: f6a66927692e ("flow_dissector: Get vlan priority in addition to vlan id") Signed-off-by: Arnd Bergmann <a...@arndb.de> --- I'm not sure about this one, please have a closer look at what the original code does before applying. --- net/core/flow_dissector.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 44e6ba9d3a6b..dd6003bf27e1 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -245,7 +245,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, } case htons(ETH_P_8021AD): case htons(ETH_P_8021Q): { - const struct vlan_hdr *vlan; + const struct vlan_hdr *vlan = NULL; if (skb && skb_vlan_tag_present(skb)) proto = skb->protocol; @@ -264,7 +264,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, } skip_vlan = true; - if (dissector_uses_key(flow_dissector, + if (vlan && dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_VLAN)) { key_vlan = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_VLAN, -- 2.9.0