Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-07-28

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) API fixes for libbpf's BTF mapping of map key/value types in order
   to make them compatible with iproute2's BPF_ANNOTATE_KV_PAIR()
   markings, from Martin.

2) Fix AF_XDP to not report POLLIN prematurely by using the non-cached
   consumer pointer of the RX queue, from Björn.

3) Fix __xdp_return() to check for NULL pointer after the rhashtable
   lookup that retrieves the allocator object, from Taehee.

4) Fix x86-32 JIT to adjust ebp register in prologue and epilogue
   by 4 bytes which got removed from overall stack usage, from Wang.

5) Fix bpf_skb_load_bytes_relative() length check to use actual
   packet length, from Daniel.

6) Fix uninitialized return code in libbpf bpf_perf_event_read_simple()
   handler, from Thomas.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 11 insertions, 8 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 06da770f543f..9dfd145eedcc 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1712,24 +1712,26 @@ static const struct bpf_func_proto bpf_skb_load_bytes_proto = {
 BPF_CALL_5(bpf_skb_load_bytes_relative, const struct sk_buff *, skb,
 	   u32, offset, void *, to, u32, len, u32, start_header)
 {
+	u8 *end = skb_tail_pointer(skb);
+	u8 *net = skb_network_header(skb);
+	u8 *mac = skb_mac_header(skb);
 	u8 *ptr;
 
-	if (unlikely(offset > 0xffff || len > skb_headlen(skb)))
+	if (unlikely(offset > 0xffff || len > (end - mac)))
 		goto err_clear;
 
 	switch (start_header) {
 	case BPF_HDR_START_MAC:
-		ptr = skb_mac_header(skb) + offset;
+		ptr = mac + offset;
 		break;
 	case BPF_HDR_START_NET:
-		ptr = skb_network_header(skb) + offset;
+		ptr = net + offset;
 		break;
 	default:
 		goto err_clear;
 	}
 
-	if (likely(ptr >= skb_mac_header(skb) &&
-		   ptr + len <= skb_tail_pointer(skb))) {
+	if (likely(ptr >= mac && ptr + len <= end)) {
 		memcpy(to, ptr, len);
 		return 0;
 	}
diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c
index e7e626fb87bb..e45098593dc0 100644
--- a/net/core/lwt_bpf.c
+++ b/net/core/lwt_bpf.c
@@ -217,7 +217,7 @@ static int bpf_parse_prog(struct nlattr *attr, struct bpf_lwt_prog *prog,
 	if (!tb[LWT_BPF_PROG_FD] || !tb[LWT_BPF_PROG_NAME])
 		return -EINVAL;
 
-	prog->name = nla_memdup(tb[LWT_BPF_PROG_NAME], GFP_KERNEL);
+	prog->name = nla_memdup(tb[LWT_BPF_PROG_NAME], GFP_ATOMIC);
 	if (!prog->name)
 		return -ENOMEM;
 
diff --git a/net/core/xdp.c b/net/core/xdp.c
index 9d1f22072d5d..6771f1855b96 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -345,7 +345,8 @@ static void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct,
 		rcu_read_lock();
 		/* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
 		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
-		xa->zc_alloc->free(xa->zc_alloc, handle);
+		if (!WARN_ON_ONCE(!xa))
+			xa->zc_alloc->free(xa->zc_alloc, handle);
 		rcu_read_unlock();
 	default:
 		/* Not possible, checked in xdp_rxq_info_reg_mem_model() */
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index 52ecaf770642..8a64b150be54 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -250,7 +250,7 @@ static inline bool xskq_full_desc(struct xsk_queue *q)
 
 static inline bool xskq_empty_desc(struct xsk_queue *q)
 {
-	return xskq_nb_free(q, q->prod_tail, 1) == q->nentries;
+	return xskq_nb_free(q, q->prod_tail, q->nentries) == q->nentries;
 }
 
 void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props);