netdev - Re: [PATCH] net: core: devlink.c: Hold devlink->lock from the beginning of devlink_dpipe_table

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20200223110145.GE2228@nanopsycho>
Date:   Sun, 23 Feb 2020 12:01:45 +0100
From:   Jiri Pirko <jiri@...nulli.us>
To:     madhuparnabhowmik10@...il.com
Cc:     jiri@...lanox.com, davem@...emloft.net, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, joel@...lfernandes.org,
        linux-kernel-mentees@...ts.linuxfoundation.org, paulmck@...nel.org
Subject: Re: [PATCH] net: core: devlink.c: Hold devlink->lock from the
 beginning of devlink_dpipe_table_register()

Sun, Feb 23, 2020 at 11:52:53AM CET, madhuparnabhowmik10@...il.com wrote:
>From: Madhuparna Bhowmik <madhuparnabhowmik10@...il.com>
>
>devlink_dpipe_table_find() should be called under either
>rcu_read_lock() or devlink->lock. devlink_dpipe_table_register()
>calls devlink_dpipe_table_find() without holding the lock
>and acquires it later. Therefore hold the devlink->lock
>from the beginning of devlink_dpipe_table_register().
>
>Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@...il.com>
>---
> net/core/devlink.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
>diff --git a/net/core/devlink.c b/net/core/devlink.c
>index 4c63c9a4c09e..61a350f59741 100644
>--- a/net/core/devlink.c
>+++ b/net/core/devlink.c
>@@ -6838,26 +6838,35 @@ int devlink_dpipe_table_register(struct devlink *devlink,
> 				 void *priv, bool counter_control_extern)
> {
> 	struct devlink_dpipe_table *table;
>+	int err = 0;
> 
>-	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name))
>-		return -EEXIST;
>+	mutex_lock(&devlink->lock);
> 
>-	if (WARN_ON(!table_ops->size_get))
>-		return -EINVAL;
>+	if (devlink_dpipe_table_find(&devlink->dpipe_table_list, table_name)) {
>+		err = -EEXIST;
>+		goto unlock;
>+	}
>+
>+	if (WARN_ON(!table_ops->size_get)) {
>+		err = -EINVAL;
>+		goto unlock;
>+	}


Put this check out of the lock please.


> 
> 	table = kzalloc(sizeof(*table), GFP_KERNEL);
>-	if (!table)
>-		return -ENOMEM;
>+	if (!table) {
>+		err = -ENOMEM;
>+		goto unlock;
>+	}
> 
> 	table->name = table_name;
> 	table->table_ops = table_ops;
> 	table->priv = priv;
> 	table->counter_control_extern = counter_control_extern;
> 
>-	mutex_lock(&devlink->lock);
> 	list_add_tail_rcu(&table->list, &devlink->dpipe_table_list);
>+unlock:
> 	mutex_unlock(&devlink->lock);
>-	return 0;
>+	return err;
> }
> EXPORT_SYMBOL_GPL(devlink_dpipe_table_register);
> 
>-- 
>2.17.1
>