[PATCH] net: avoid uninitialized variable
From: zhongjiang <hidden>
Date: 2016-10-27 03:58:52
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: zhong jiang <redacted> when I compiler the newest kernel, I hit the following error with Werror=may-uninitalized. net/core/flow_dissector.c: In function ?._skb_flow_dissect? include/uapi/linux/swab.h:100:46: error: ?.lan?.may be used uninitialized in this function [-Werror=maybe-uninitialized] net/core/flow_dissector.c:248:26: note: ?.lan?.was declared here This adds an additional check for proto to explicitly tell the compiler that vlan pointer have the correct value before it is used. Signed-off-by: zhong jiang <redacted> --- net/core/flow_dissector.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 1a7b80f..a04d9cf 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_vlan_tag_present(skb)) proto = skb->protocol;
@@ -276,7 +276,8 @@ bool __skb_flow_dissect(const struct sk_buff *skb, key_vlan->vlan_id = skb_vlan_tag_get_id(skb); key_vlan->vlan_priority = (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT); - } else { + } else if (proto == cpu_to_be16(ETH_P_8021Q) || + proto == cpu_to_be16(ETH_P_8021AD)) { key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & VLAN_VID_MASK; key_vlan->vlan_priority =
--
1.8.3.1