Re: [PATCH] LLC: Avoid potential NULL dereference in net/llc/af_llc.c::llc_ui_accept() .

From: Jesper Juhl
Date: Wed Nov 01 2006 - 19:30:43 EST


On 02/11/06, David Miller <davem@xxxxxxxxxxxxx> wrote:
From: Jesper Juhl <jesper.juhl@xxxxxxxxx>
Date: Thu, 2 Nov 2006 01:21:53 +0100

> Since skb_dequeue() may return NULL we risk dereferencing a NULL pointer at
> if (!skb->sk)
> This patch avoids that by also testing for a NULL skb.
>
>
> Signed-off-by: Jesper Juhl <jesper.juhl@xxxxxxxxx>

It can't return NULL in this context because we just checked
skb_queue_empty() with the socket lock held and llc_wait_data()
will return zero only if skb_queue_empty() is false.

I know it's hard for automated tools to see this, but it's not
reasonable to put this extra check in there since it is
superfluous due to the above mentioned invariants.

Fair enough. Ignore the patch.
Thank you for the explanation.

--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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