net: add __rcu annotations to sk_wq and wq

Add proper RCU annotations/verbs to sk_wq and wq members

Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access)

Fix sunrpc sk_sleep() abuse too

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 9 deletions

diff --git a/net/socket.c b/net/socket.c
index ac2219f90d5d..9fa1e3b4366e 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -240,17 +240,19 @@ static struct kmem_cache *sock_inode_cachep __read_mostly;
 static struct inode *sock_alloc_inode(struct super_block *sb)
 {
         struct socket_alloc *ei;
+        struct socket_wq *wq;
 
         ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
         if (!ei)
                 return NULL;
-        ei->socket.wq = kmalloc(sizeof(struct socket_wq), GFP_KERNEL);
-        if (!ei->socket.wq) {
+        wq = kmalloc(sizeof(*wq), GFP_KERNEL);
+        if (!wq) {
                 kmem_cache_free(sock_inode_cachep, ei);
                 return NULL;
         }
-        init_waitqueue_head(&ei->socket.wq->wait);
-        ei->socket.wq->fasync_list = NULL;
+        init_waitqueue_head(&wq->wait);
+        wq->fasync_list = NULL;
+        RCU_INIT_POINTER(ei->socket.wq, wq);
 
         ei->socket.state = SS_UNCONNECTED;
         ei->socket.flags = 0;
@@ -273,9 +275,11 @@ static void wq_free_rcu(struct rcu_head *head)
 static void sock_destroy_inode(struct inode *inode)
 {
         struct socket_alloc *ei;
+        struct socket_wq *wq;
 
         ei = container_of(inode, struct socket_alloc, vfs_inode);
-        call_rcu(&ei->socket.wq->rcu, wq_free_rcu);
+        wq = rcu_dereference_protected(ei->socket.wq, 1);
+        call_rcu(&wq->rcu, wq_free_rcu);
         kmem_cache_free(sock_inode_cachep, ei);
 }
 
@@ -524,7 +528,7 @@ void sock_release(struct socket *sock)
                 module_put(owner);
         }
 
-        if (sock->wq->fasync_list)
+        if (rcu_dereference_protected(sock->wq, 1)->fasync_list)
                 printk(KERN_ERR "sock_release: fasync list not empty!\n");
 
         percpu_sub(sockets_in_use, 1);
@@ -1108,15 +1112,16 @@ static int sock_fasync(int fd, struct file *filp, int on)
 {
         struct socket *sock = filp->private_data;
         struct sock *sk = sock->sk;
+        struct socket_wq *wq;
 
         if (sk == NULL)
                 return -EINVAL;
 
         lock_sock(sk);
+        wq = rcu_dereference_protected(sock->wq, sock_owned_by_user(sk));
+        fasync_helper(fd, filp, on, &wq->fasync_list);
 
-        fasync_helper(fd, filp, on, &sock->wq->fasync_list);
-
-        if (!sock->wq->fasync_list)
+        if (!wq->fasync_list)
                 sock_reset_flag(sk, SOCK_FASYNC);
         else
                 sock_set_flag(sk, SOCK_FASYNC);