Revert: "crypto: af_alg - Disallow bind/setkey/... after accept(2)"

This reverts commit 5a707f0972e1c9d8a4a921ddae79d0f9dc36a341 which is
commit c840ac6af3f8713a71b4d2363419145760bd6044 upstream.

It's been widely reported that this patch breaks existing userspace
applications when backported to the stable kernel releases.  As no fix
seems to be forthcoming, just revert it to let systems work again.

Reported-by: "J. Paul Reed" <preed@sigkill.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 0ca108f3c84084278c026173302cccfdce0a487f..1aaa555fab56b6e6fa127fe546e14d7fa69b4a40 100644 (file)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -125,23 +125,6 @@ int af_alg_release(struct socket *sock)
 }
 EXPORT_SYMBOL_GPL(af_alg_release);
 
-void af_alg_release_parent(struct sock *sk)
-{
-       struct alg_sock *ask = alg_sk(sk);
-       bool last;
-
-       sk = ask->parent;
-       ask = alg_sk(sk);
-
-       lock_sock(sk);
-       last = !--ask->refcnt;
-       release_sock(sk);
-
-       if (last)
-               sock_put(sk);
-}
-EXPORT_SYMBOL_GPL(af_alg_release_parent);
-
 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
        struct sock *sk = sock->sk;
@@ -149,7 +132,6 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
        struct sockaddr_alg *sa = (void *)uaddr;
        const struct af_alg_type *type;
        void *private;
-       int err;
 
        if (sock->state == SS_CONNECTED)
                return -EINVAL;
@@ -175,22 +157,16 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
                return PTR_ERR(private);
        }
 
-       err = -EBUSY;
        lock_sock(sk);
-       if (ask->refcnt)
-               goto unlock;
 
        swap(ask->type, type);
        swap(ask->private, private);
 
-       err = 0;
-
-unlock:
        release_sock(sk);
 
        alg_do_release(type, private);
 
-       return err;
+       return 0;
 }
 
 static int alg_setkey(struct sock *sk, char __user *ukey,
@@ -223,15 +199,11 @@ static int alg_setsockopt(struct socket *sock, int level, int optname,
        struct sock *sk = sock->sk;
        struct alg_sock *ask = alg_sk(sk);
        const struct af_alg_type *type;
-       int err = -EBUSY;
+       int err = -ENOPROTOOPT;
 
        lock_sock(sk);
-       if (ask->refcnt)
-               goto unlock;
-
        type = ask->type;
 
-       err = -ENOPROTOOPT;
        if (level != SOL_ALG || !type)
                goto unlock;
 
@@ -280,8 +252,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 
        sk2->sk_family = PF_ALG;
 
-       if (!ask->refcnt++)
-               sock_hold(sk);
+       sock_hold(sk);
        alg_sk(sk2)->parent = sk;
        alg_sk(sk2)->type = type;
 

diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index 2f38daaab3d768538ee5c06352114423b2ceda85..d61c11170213f22dd95467959aed5596b1edc5a5 100644 (file)
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -30,8 +30,6 @@ struct alg_sock {
 
        struct sock *parent;
 
-       unsigned int refcnt;
-
        const struct af_alg_type *type;
        void *private;
 };
@@ -66,7 +64,6 @@ int af_alg_register_type(const struct af_alg_type *type);
 int af_alg_unregister_type(const struct af_alg_type *type);
 
 int af_alg_release(struct socket *sock);
-void af_alg_release_parent(struct sock *sk);
 int af_alg_accept(struct sock *sk, struct socket *newsock);
 
 int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
@@ -83,6 +80,11 @@ static inline struct alg_sock *alg_sk(struct sock *sk)
        return (struct alg_sock *)sk;
 }
 
+static inline void af_alg_release_parent(struct sock *sk)
+{
+       sock_put(alg_sk(sk)->parent);
+}
+
 static inline void af_alg_init_completion(struct af_alg_completion *completion)
 {
        init_completion(&completion->completion);