Merge branch 'sockhash-fixes'

John Fastabend says:

====================
First three patches resolve issues found while testing sockhash and
reviewing code. Syzbot also found them about the same time as I was
working on fixes. The main issue is in the sockhash path we reduced
the scope of sk_callback lock but this meant we could get update and
close running in parallel so fix that here.

Then testing sk_msg and sk_skb programs together found that skb->dev
is not always assigned and some of the helpers were depending on this
to lookup max mtu. Fix this by using SKB_MAX_ALLOC when no MTU is
available.

Finally, Martin spotted that the sockmap code was still using the
qdisc skb cb structure. But I was sure we had fixed this long ago.
Looks like we missed it in a merge conflict resolution and then by
chance data_end offset was the same in both structures so everything
sort of continued to work even though it could break at any moment
if the structs ever change. So redo the conversion and this time
also convert the helpers.

v2: fix '0 files changed' issue in patches
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

2 files changed, 24 insertions, 4 deletions

diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 00fb2e328d1b..98fb7938beea 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -312,10 +312,12 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
         struct smap_psock *psock;
         struct sock *osk;
 
+        lock_sock(sk);
         rcu_read_lock();
         psock = smap_psock_sk(sk);
         if (unlikely(!psock)) {
                 rcu_read_unlock();
+                release_sock(sk);
                 return sk->sk_prot->close(sk, timeout);
         }
 
@@ -371,6 +373,7 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
                 e = psock_map_pop(sk, psock);
         }
         rcu_read_unlock();
+        release_sock(sk);
         close_fun(sk, timeout);
 }
 
@@ -568,7 +571,8 @@ static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
         while (sg[i].length) {
                 free += sg[i].length;
                 sk_mem_uncharge(sk, sg[i].length);
-                put_page(sg_page(&sg[i]));
+                if (!md->skb)
+                        put_page(sg_page(&sg[i]));
                 sg[i].length = 0;
                 sg[i].page_link = 0;
                 sg[i].offset = 0;
@@ -577,6 +581,8 @@ static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
                 if (i == MAX_SKB_FRAGS)
                         i = 0;
         }
+        if (md->skb)
+                consume_skb(md->skb);
 
         return free;
 }
@@ -1230,7 +1236,7 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
          */
         TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
         skb->sk = psock->sock;
-        bpf_compute_data_pointers(skb);
+        bpf_compute_data_end_sk_skb(skb);
         preempt_disable();
         rc = (*prog->bpf_func)(skb, prog->insnsi);
         preempt_enable();
@@ -1485,7 +1491,7 @@ static int smap_parse_func_strparser(struct strparser *strp,
          * any socket yet.
          */
         skb->sk = psock->sock;
-        bpf_compute_data_pointers(skb);
+        bpf_compute_data_end_sk_skb(skb);
         rc = (*prog->bpf_func)(skb, prog->insnsi);
         skb->sk = NULL;
         rcu_read_unlock();
@@ -2069,7 +2075,13 @@ static int sock_map_update_elem(struct bpf_map *map,
                 return -EOPNOTSUPP;
         }
 
+        lock_sock(skops.sk);
+        preempt_disable();
+        rcu_read_lock();
         err = sock_map_ctx_update_elem(&skops, map, key, flags);
+        rcu_read_unlock();
+        preempt_enable();
+        release_sock(skops.sk);
         fput(socket->file);
         return err;
 }
@@ -2410,7 +2422,13 @@ static int sock_hash_update_elem(struct bpf_map *map,
                 return -EINVAL;
         }
 
+        lock_sock(skops.sk);
+        preempt_disable();
+        rcu_read_lock();
         err = sock_hash_ctx_update_elem(&skops, map, key, flags);
+        rcu_read_unlock();
+        preempt_enable();
+        release_sock(skops.sk);
         fput(socket->file);
         return err;
 }
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index d10ecd78105f..a31a1ba0f8ea 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -735,7 +735,9 @@ static int map_update_elem(union bpf_attr *attr)
         if (bpf_map_is_dev_bound(map)) {
                 err = bpf_map_offload_update_elem(map, key, value, attr->flags);
                 goto out;
-        } else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
+        } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
+                   map->map_type == BPF_MAP_TYPE_SOCKHASH ||
+                   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
                 err = map->ops->map_update_elem(map, key, value, attr->flags);
                 goto out;
         }