Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Tue, 08 Jul 2014 20:01:50 +0100 | Subject | [PATCH 3.2 125/125] skbuff: skb_segment: orphan frags before copying |
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3.2.61-rc1 review patch. If anyone has any objections, please let me know.
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From: "Michael S. Tsirkin" <mst@redhat.com>
commit 1fd819ecb90cc9b822cd84d3056ddba315d3340f upstream.
skb_segment copies frags around, so we need to copy them carefully to avoid accessing user memory after reporting completion to userspace through a callback.
skb_segment doesn't normally happen on datapath: TSO needs to be disabled - so disabling zero copy in this case does not look like a big deal.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2. As skb_segment() only supports page-frags *or* a frag list, there is no need for the additional frag_skb pointer or the preparatory renaming.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2698,6 +2698,9 @@ struct sk_buff *skb_segment(struct sk_bu skb_put(nskb, hsize), hsize); while (pos < offset + len && i < nfrags) { + if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) + goto err; + *frag = skb_shinfo(skb)->frags[i]; __skb_frag_ref(frag); size = skb_frag_size(frag);
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