| Message ID | 1455872354-26032-2-git-send-email-aar@pengutronix.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
diff --git a/include/net/mac802154.h b/include/net/mac802154.h index da574bb..2e3cdd20 100644 --- a/include/net/mac802154.h +++ b/include/net/mac802154.h @@ -247,8 +247,9 @@ struct ieee802154_ops { */ static inline __le16 ieee802154_get_fc_from_skb(const struct sk_buff *skb) { - /* return some invalid fc on failure */ - if (unlikely(skb->len < 2)) { + /* check if we can fc at skb_mac_header of sk buffer */ + if (unlikely(!skb_mac_header_was_set(skb) || + (skb_tail_pointer(skb) - skb_mac_header(skb)) < 2)) { WARN_ON(1); return cpu_to_le16(0); }
I got report about that sometimes the WARN_ON occurs there which should never happen. I came to the conclusion that the mac header is there but inside the headroom of skb. The skb->len information doesn't contain the information about the headroom length and skb->len is lesser than two. We check now if the skb_mac_header pointer is set and the room between mac header pointer and tail pointer. Signed-off-by: Alexander Aring <aar@pengutronix.de> --- include/net/mac802154.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)