net/tls: sleeping function from invalid context

HW unhash within mutex for registered tls devices cause sleep
when called from tcp_set_state for TCP_CLOSE. Release lock and
re-acquire after function call with ref count incr/dec.
defined kref and fp release for tls_device to ensure device
is not released outside lock.

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:748
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/7
INFO: lockdep is turned off.
CPU: 7 PID: 0 Comm: swapper/7 Tainted: G        W  O
Call Trace:
 <IRQ>
 dump_stack+0x5e/0x8b
 ___might_sleep+0x222/0x260
 __mutex_lock+0x5c/0xa50
 ? vprintk_emit+0x1f3/0x440
 ? kmem_cache_free+0x22d/0x2a0
 ? tls_hw_unhash+0x2f/0x80
 ? printk+0x52/0x6e
 ? tls_hw_unhash+0x2f/0x80
 tls_hw_unhash+0x2f/0x80
 tcp_set_state+0x5f/0x180
 tcp_done+0x2e/0xe0
 tcp_rcv_state_process+0x92c/0xdd3
 ? lock_acquire+0xf5/0x1f0
 ? tcp_v4_rcv+0xa7c/0xbe0
 ? tcp_v4_do_rcv+0x70/0x1e0

Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 13 deletions

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 492080306edc..1428bd74638c 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -56,7 +56,7 @@ enum {
 static struct proto *saved_tcpv6_prot;
 static DEFINE_MUTEX(tcpv6_prot_mutex);
 static LIST_HEAD(device_list);
-static DEFINE_MUTEX(device_mutex);
+static DEFINE_SPINLOCK(device_spinlock);
 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
 static struct proto_ops tls_sw_proto_ops;
 
@@ -555,7 +555,7 @@ static int tls_hw_prot(struct sock *sk)
 	struct tls_device *dev;
 	int rc = 0;
 
-	mutex_lock(&device_mutex);
+	spin_lock_bh(&device_spinlock);
 	list_for_each_entry(dev, &device_list, dev_list) {
 		if (dev->feature && dev->feature(dev)) {
 			ctx = create_ctx(sk);
@@ -573,7 +573,7 @@ static int tls_hw_prot(struct sock *sk)
 		}
 	}
 out:
-	mutex_unlock(&device_mutex);
+	spin_unlock_bh(&device_spinlock);
 	return rc;
 }
 
@@ -582,12 +582,17 @@ static void tls_hw_unhash(struct sock *sk)
 	struct tls_context *ctx = tls_get_ctx(sk);
 	struct tls_device *dev;
 
-	mutex_lock(&device_mutex);
+	spin_lock_bh(&device_spinlock);
 	list_for_each_entry(dev, &device_list, dev_list) {
-		if (dev->unhash)
+		if (dev->unhash) {
+			kref_get(&dev->kref);
+			spin_unlock_bh(&device_spinlock);
 			dev->unhash(dev, sk);
+			kref_put(&dev->kref, dev->release);
+			spin_lock_bh(&device_spinlock);
+		}
 	}
-	mutex_unlock(&device_mutex);
+	spin_unlock_bh(&device_spinlock);
 	ctx->unhash(sk);
 }
 
@@ -598,12 +603,17 @@ static int tls_hw_hash(struct sock *sk)
 	int err;
 
 	err = ctx->hash(sk);
-	mutex_lock(&device_mutex);
+	spin_lock_bh(&device_spinlock);
 	list_for_each_entry(dev, &device_list, dev_list) {
-		if (dev->hash)
+		if (dev->hash) {
+			kref_get(&dev->kref);
+			spin_unlock_bh(&device_spinlock);
 			err |= dev->hash(dev, sk);
+			kref_put(&dev->kref, dev->release);
+			spin_lock_bh(&device_spinlock);
+		}
 	}
-	mutex_unlock(&device_mutex);
+	spin_unlock_bh(&device_spinlock);
 
 	if (err)
 		tls_hw_unhash(sk);
@@ -699,17 +709,17 @@ out:
 
 void tls_register_device(struct tls_device *device)
 {
-	mutex_lock(&device_mutex);
+	spin_lock_bh(&device_spinlock);
 	list_add_tail(&device->dev_list, &device_list);
-	mutex_unlock(&device_mutex);
+	spin_unlock_bh(&device_spinlock);
 }
 EXPORT_SYMBOL(tls_register_device);
 
 void tls_unregister_device(struct tls_device *device)
 {
-	mutex_lock(&device_mutex);
+	spin_lock_bh(&device_spinlock);
 	list_del(&device->dev_list);
-	mutex_unlock(&device_mutex);
+	spin_unlock_bh(&device_spinlock);
 }
 EXPORT_SYMBOL(tls_unregister_device);