1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index adeee615dd19..c9a15925a1f7 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -310,6 +310,7 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 			     const char *buf,
 			     size_t count)
 {
+	unsigned long flags;
 	int enabled;
 	int err;
 
@@ -324,9 +325,7 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 		return -EINVAL;
 	}
 
-	mutex_lock(&nt->mutex);
 	if (enabled) {	/* 1 */
-
 		/*
 		 * Skip netpoll_parse_options() -- all the attributes are
 		 * already configured via configfs. Just print them out.
@@ -334,19 +333,22 @@ static ssize_t store_enabled(struct netconsole_target *nt,
 		netpoll_print_options(&nt->np);
 
 		err = netpoll_setup(&nt->np);
-		if (err) {
-			mutex_unlock(&nt->mutex);
+		if (err)
 			return err;
-		}
 
 		printk(KERN_INFO "netconsole: network logging started\n");
-
 	} else {	/* 0 */
+		/* We need to disable the netconsole before cleaning it up
+		 * otherwise we might end up in write_msg() with
+		 * nt->np.dev == NULL and nt->enabled == 1
+		 */
+		spin_lock_irqsave(&target_list_lock, flags);
+		nt->enabled = 0;
+		spin_unlock_irqrestore(&target_list_lock, flags);
 		netpoll_cleanup(&nt->np);
 	}
 
 	nt->enabled = enabled;
-	mutex_unlock(&nt->mutex);
 
 	return strnlen(buf, count);
 }
@@ -563,8 +565,10 @@ static ssize_t netconsole_target_attr_store(struct config_item *item,
 	struct netconsole_target_attr *na =
 		container_of(attr, struct netconsole_target_attr, attr);
 
+	mutex_lock(&nt->mutex);
 	if (na->store)
 		ret = na->store(nt, buf, count);
+	mutex_unlock(&nt->mutex);
 
 	return ret;
 }