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  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:	Mon, 01 Oct 2007 18:58:15 +0400
From:	"Denis V. Lunev" <>
To:	Patrick McHardy <>
CC:	"Denis V. Lunev" <>,,, "Eric W. Biederman" <>
Subject: Re: [PATCH] memory leak in netlink user->kernel processing

Patrick McHardy wrote:
> Denis V. Lunev wrote:
>> netlink_kernel_create can be called with NULL as an input callback in several
>> places, f.e. in kobject_uevent_init. This means that if one sends packet from
>> user to kernel for such a socket, the packet will be leaked in the socket
>> queue forever.
>> This patch adds a simple generic cleanup callback for these sockets.
> This should already be handled by netlink_getsockbypid:
>         /* Don't bother queuing skb if kernel socket has no input
> function */
>         nlk = nlk_sk(sock);
>         if ((nlk->pid == 0 && !nlk->data_ready) ||
>             (sock->sk_state == NETLINK_CONNECTED &&
>              nlk->dst_pid != nlk_sk(ssk)->pid)) {
>                 sock_put(sock);
>                 return ERR_PTR(-ECONNREFUSED);
>         }
> -
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to
> More majordomo info at

Looks so...

By the way, Patrick, this looks like nlk->pid == 0 if and only if this
is a kernel socket. Right?

I have told with Alexey Kuznetsov and we have discrovered a way to get
rid of
        skb_queue_tail(&sk->sk_receive_queue, skb);
        sk->sk_data_ready(sk, len);
in netlink_sendskb/etc for kernel sockets and make user->kernel packets
processing truly synchronous.

The idea is simple, we should queue/wakeup in kernel->user direction and
simply call nlk->data_ready for user->kernel direction. This will remove
all the crap we have now. But we need a mark to determine the direction.
Which one will be better? (nlk->data_ready) or (nlk->pid == 0)

To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists