netdev - Re: [PATCH net-next v6 1/8] vxlan: Restructure vxlan socket apis.

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

Date:	Sun, 4 Aug 2013 14:42:15 -0700
From:	Stephen Hemminger <stephen@...workplumber.org>
To:	Pravin B Shelar <pshelar@...ira.com>
Cc:	netdev@...r.kernel.org
Subject: Re: [PATCH net-next v6 1/8] vxlan: Restructure vxlan socket apis.

On Thu,  1 Aug 2013 11:44:40 -0700
Pravin B Shelar <pshelar@...ira.com> wrote:

> @@ -1642,59 +1651,56 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, __be16 port)
>  			 &vxlan_addr.sin_addr, ntohs(vxlan_addr.sin_port), rc);
>  		sk_release_kernel(sk);
>  		kfree(vs);
> -		return ERR_PTR(rc);
> +		return;
>  	}
> +	atomic_set(&vs->refcnt, 0);
>  
>  	/* Disable multicast loopback */
>  	inet_sk(sk)->mc_loop = 0;
> +	spin_lock(&vn->sock_lock);
> +	hlist_add_head_rcu(&vs->hlist, vs_head(net, port));
> +	spin_unlock(&vn->sock_lock);

Overall I am fine with this set, except for this.
The change causes a socket to be put into the hash list with a ref count
of 0 and then you increment the ref count. If some other thread
finds the socket and then decrements the ref count, it would go
below zero and might leak, crash or delete it prematurely.

This concerns me. 
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html