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From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: jasowang@redhat.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	mst@redhat.com
Subject: Re: [PATCH] net: sock: validate data_len before allocating skb in sock_alloc_send_pskb()
Date: Wed, 30 May 2012 03:02:05 -0400 (EDT)	[thread overview]
Message-ID: <20120530.030205.1337682162603770949.davem@davemloft.net> (raw)
In-Reply-To: <1338360383.2760.84.camel@edumazet-glaptop>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 30 May 2012 08:46:23 +0200

> Why doing this test in the while (1) block, it should be done before the
> loop...
> 
> Or even in the caller, note net/unix/af_unix.c does this right.
> 
>         if (len > SKB_MAX_ALLOC)
>                 data_len = min_t(size_t,
>                                  len - SKB_MAX_ALLOC,
>                                  MAX_SKB_FRAGS * PAGE_SIZE);
> 
>         skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
>                                    msg->msg_flags & MSG_DONTWAIT, &err);

My impression is that the callers should be fixed to.  It makes no sense
to penalize the call sites that get this right.

And yes, if we do check it in sock_alloc_send_pskb() it should be done
at function entry, not inside the loop.

  reply	other threads:[~2012-05-30  7:02 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-30  5:47 [PATCH] net: sock: validate data_len before allocating skb in sock_alloc_send_pskb() Jason Wang
2012-05-30  6:46 ` Eric Dumazet
2012-05-30  7:02   ` David Miller [this message]
2012-05-31  6:00     ` Jason Wang
2012-05-31  6:02       ` Michael S. Tsirkin
2012-05-31  6:11         ` Jason Wang
2012-05-31  6:20           ` Eric Dumazet
2012-05-31  6:43             ` Jason Wang

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