From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH 2/4] net: make skb_gso_segment error handling more
 robust
Date: Sun, 19 Oct 2014 20:39:43 -0400 (EDT)
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From: Florian Westphal <fw@strlen.de>
Date: Sun, 19 Oct 2014 22:42:19 +0200

> skb_gso_segment has three possible return values:
> 1. a pointer to the first segmented skb
> 2. an errno value (IS_ERR())
> 3. NULL.  This can happen when GSO is used for header verification.
> 
> However, several callers currently test IS_ERR instead of IS_ERR_OR_NULL
> and would oops when NULL is returned.
> 
> Note that these call sites should never actually see such a NULL return
> value; all callers mask out the GSO bits in the feature argument.
> 
> However, in the past, there have been issues with some protocol handlers
> erronously not respecting the specified feature mask in some cases.
> 
> Signed-off-by: Florian Westphal <fw@strlen.de>

I don't think it makes sense to return PTR_ERR(p) when
p is NULL.