diff options
| -rw-r--r-- | include/net/neighbour.h | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 8b683841e574..f6017ddc4ded 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -448,6 +448,7 @@ static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) { + unsigned int hh_alen = 0; unsigned int seq; int hh_len; @@ -455,16 +456,33 @@ static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb seq = read_seqbegin(&hh->hh_lock); hh_len = hh->hh_len; if (likely(hh_len <= HH_DATA_MOD)) { - /* this is inlined by gcc */ - memcpy(skb->data - HH_DATA_MOD, hh->hh_data, HH_DATA_MOD); + hh_alen = HH_DATA_MOD; + + /* skb_push() would proceed silently if we have room for + * the unaligned size but not for the aligned size: + * check headroom explicitly. + */ + if (likely(skb_headroom(skb) >= HH_DATA_MOD)) { + /* this is inlined by gcc */ + memcpy(skb->data - HH_DATA_MOD, hh->hh_data, + HH_DATA_MOD); + } } else { - int hh_alen = HH_DATA_ALIGN(hh_len); + hh_alen = HH_DATA_ALIGN(hh_len); - memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); + if (likely(skb_headroom(skb) >= hh_alen)) { + memcpy(skb->data - hh_alen, hh->hh_data, + hh_alen); + } } } while (read_seqretry(&hh->hh_lock, seq)); - skb_push(skb, hh_len); + if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) { + kfree_skb(skb); + return NET_XMIT_DROP; + } + + __skb_push(skb, hh_len); return dev_queue_xmit(skb); } |