1 files changed, 10 insertions, 3 deletions

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 8974b3755670..3c18260403dd 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -162,10 +162,14 @@ static void cpu_map_kthread_stop(struct work_struct *work)
 static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
                                          struct xdp_frame *xdpf)
 {
+        unsigned int hard_start_headroom;
         unsigned int frame_size;
         void *pkt_data_start;
         struct sk_buff *skb;
 
+        /* Part of headroom was reserved to xdpf */
+        hard_start_headroom = sizeof(struct xdp_frame) +  xdpf->headroom;
+
         /* build_skb need to place skb_shared_info after SKB end, and
          * also want to know the memory "truesize".  Thus, need to
          * know the memory frame size backing xdp_buff.
@@ -183,15 +187,15 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
          * is not at a fixed memory location, with mixed length
          * packets, which is bad for cache-line hotness.
          */
-        frame_size = SKB_DATA_ALIGN(xdpf->len + xdpf->headroom) +
+        frame_size = SKB_DATA_ALIGN(xdpf->len + hard_start_headroom) +
                 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 
-        pkt_data_start = xdpf->data - xdpf->headroom;
+        pkt_data_start = xdpf->data - hard_start_headroom;
         skb = build_skb(pkt_data_start, frame_size);
         if (!skb)
                 return NULL;
 
-        skb_reserve(skb, xdpf->headroom);
+        skb_reserve(skb, hard_start_headroom);
         __skb_put(skb, xdpf->len);
         if (xdpf->metasize)
                 skb_metadata_set(skb, xdpf->metasize);
@@ -205,6 +209,9 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
          * - RX ring dev queue index    (skb_record_rx_queue)
          */
 
+        /* Allow SKB to reuse area used by xdp_frame */
+        xdp_scrub_frame(xdpf);
+
         return skb;
 }