Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - fix chacha20 crash on zero-length input due to unset IV

   - fix potential race conditions in mcryptd with spinlock

   - only wait once at top of algif recvmsg to avoid inconsistencies

   - fix potential use-after-free in algif_aead/algif_skcipher"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: af_alg - fix race accessing cipher request
  crypto: mcryptd - protect the per-CPU queue with a lock
  crypto: af_alg - wait for data at beginning of recvmsg
  crypto: skcipher - set walk.iv for zero-length inputs

crypto/af_alg.c

@@ -1138,12 +1138,6 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
 		if (!af_alg_readable(sk))
 			break;
 
-		if (!ctx->used) {
-			err = af_alg_wait_for_data(sk, flags);
-			if (err)
-				return err;
-		}
-
 		seglen = min_t(size_t, (maxsize - len),
 			       msg_data_left(msg));
 

crypto/algif_aead.c

@@ -111,6 +111,12 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 	size_t usedpages = 0;		/* [in]  RX bufs to be used from user */
 	size_t processed = 0;		/* [in]  TX bufs to be consumed */
 
+	if (!ctx->used) {
+		err = af_alg_wait_for_data(sk, flags);
+		if (err)
+			return err;
+	}
+
 	/*
 	 * Data length provided by caller via sendmsg/sendpage that has not
 	 * yet been processed.
@@ -285,6 +291,10 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 		/* AIO operation */
 		sock_hold(sk);
 		areq->iocb = msg->msg_iocb;
+
+		/* Remember output size that will be generated. */
+		areq->outlen = outlen;
+
 		aead_request_set_callback(&areq->cra_u.aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
 					  af_alg_async_cb, areq);
@@ -292,12 +302,8 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
 				 crypto_aead_decrypt(&areq->cra_u.aead_req);
 
 		/* AIO operation in progress */
-		if (err == -EINPROGRESS || err == -EBUSY) {
-			/* Remember output size that will be generated. */
-			areq->outlen = outlen;
-
+		if (err == -EINPROGRESS || err == -EBUSY)
 			return -EIOCBQUEUED;
-		}
 
 		sock_put(sk);
 	} else {

crypto/algif_skcipher.c

@@ -72,6 +72,12 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 	int err = 0;
 	size_t len = 0;
 
+	if (!ctx->used) {
+		err = af_alg_wait_for_data(sk, flags);
+		if (err)
+			return err;
+	}
+
 	/* Allocate cipher request for current operation. */
 	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
 				     crypto_skcipher_reqsize(tfm));
@@ -119,6 +125,10 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 		/* AIO operation */
 		sock_hold(sk);
 		areq->iocb = msg->msg_iocb;
+
+		/* Remember output size that will be generated. */
+		areq->outlen = len;
+
 		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
 					      CRYPTO_TFM_REQ_MAY_SLEEP,
 					      af_alg_async_cb, areq);
@@ -127,12 +137,8 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
 			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
 
 		/* AIO operation in progress */
-		if (err == -EINPROGRESS || err == -EBUSY) {
-			/* Remember output size that will be generated. */
-			areq->outlen = len;
-
+		if (err == -EINPROGRESS || err == -EBUSY)
 			return -EIOCBQUEUED;
-		}
 
 		sock_put(sk);
 	} else {

crypto/mcryptd.c

@@ -81,6 +81,7 @@ static int mcryptd_init_queue(struct mcryptd_queue *queue,
 		pr_debug("cpu_queue #%d %p\n", cpu, queue->cpu_queue);
 		crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
 		INIT_WORK(&cpu_queue->work, mcryptd_queue_worker);
+		spin_lock_init(&cpu_queue->q_lock);
 	}
 	return 0;
 }
@@ -104,15 +105,16 @@ static int mcryptd_enqueue_request(struct mcryptd_queue *queue,
 	int cpu, err;
 	struct mcryptd_cpu_queue *cpu_queue;
 
-	cpu = get_cpu();
-	cpu_queue = this_cpu_ptr(queue->cpu_queue);
-	rctx->tag.cpu = cpu;
+	cpu_queue = raw_cpu_ptr(queue->cpu_queue);
+	spin_lock(&cpu_queue->q_lock);
+	cpu = smp_processor_id();
+	rctx->tag.cpu = smp_processor_id();
 
 	err = crypto_enqueue_request(&cpu_queue->queue, request);
 	pr_debug("enqueue request: cpu %d cpu_queue %p request %p\n",
 		 cpu, cpu_queue, request);
+	spin_unlock(&cpu_queue->q_lock);
 	queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);
-	put_cpu();
 
 	return err;
 }
@@ -161,16 +163,11 @@ static void mcryptd_queue_worker(struct work_struct *work)
 	cpu_queue = container_of(work, struct mcryptd_cpu_queue, work);
 	i = 0;
 	while (i < MCRYPTD_BATCH || single_task_running()) {
-		/*
-		 * preempt_disable/enable is used to prevent
-		 * being preempted by mcryptd_enqueue_request()
-		 */
-		local_bh_disable();
-		preempt_disable();
+
+		spin_lock_bh(&cpu_queue->q_lock);
 		backlog = crypto_get_backlog(&cpu_queue->queue);
 		req = crypto_dequeue_request(&cpu_queue->queue);
-		preempt_enable();
-		local_bh_enable();
+		spin_unlock_bh(&cpu_queue->q_lock);
 
 		if (!req) {
 			mcryptd_opportunistic_flush();
@@ -185,7 +182,7 @@ static void mcryptd_queue_worker(struct work_struct *work)
 		++i;
 	}
 	if (cpu_queue->queue.qlen)
-		queue_work(kcrypto_wq, &cpu_queue->work);
+		queue_work_on(smp_processor_id(), kcrypto_wq, &cpu_queue->work);
 }
 
 void mcryptd_flusher(struct work_struct *__work)

crypto/skcipher.c

@@ -449,6 +449,8 @@ static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 
 	walk->total = req->cryptlen;
 	walk->nbytes = 0;
+	walk->iv = req->iv;
+	walk->oiv = req->iv;
 
 	if (unlikely(!walk->total))
 		return 0;
@@ -456,9 +458,6 @@ static int skcipher_walk_skcipher(struct skcipher_walk *walk,
 	scatterwalk_start(&walk->in, req->src);
 	scatterwalk_start(&walk->out, req->dst);
 
-	walk->iv = req->iv;
-	walk->oiv = req->iv;
-
 	walk->flags &= ~SKCIPHER_WALK_SLEEP;
 	walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 		       SKCIPHER_WALK_SLEEP : 0;
@@ -510,6 +509,8 @@ static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 	int err;
 
 	walk->nbytes = 0;
+	walk->iv = req->iv;
+	walk->oiv = req->iv;
 
 	if (unlikely(!walk->total))
 		return 0;
@@ -525,9 +526,6 @@ static int skcipher_walk_aead_common(struct skcipher_walk *walk,
 	scatterwalk_done(&walk->in, 0, walk->total);
 	scatterwalk_done(&walk->out, 0, walk->total);
 
-	walk->iv = req->iv;
-	walk->oiv = req->iv;
-
 	if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
 		walk->flags |= SKCIPHER_WALK_SLEEP;
 	else

include/crypto/mcryptd.h

@@ -27,6 +27,7 @@ static inline struct mcryptd_ahash *__mcryptd_ahash_cast(
 
 struct mcryptd_cpu_queue {
 	struct crypto_queue queue;
+	spinlock_t q_lock;
 	struct work_struct work;
 };