From b124695c12cb8c4dc0f91cc18eac640f546c6456 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 10 Mar 2014 19:28:08 +0200 Subject: [PATCH] skbuff: skb_segment: orphan frags before copying 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 Acked-by: Herbert Xu Signed-off-by: David S. Miller [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 Cc: Eddie Chapman # backported to 3.10 Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 66f722b..9f84a5f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2844,6 +2844,8 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG; 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); -- 2.7.4