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authorMichael S. Tsirkin <mst@redhat.com>2014-03-10 19:28:08 +0200
committerDavid S. Miller <davem@davemloft.net>2014-03-11 16:26:38 -0400
commit1fd819ecb90cc9b822cd84d3056ddba315d3340f (patch)
treea6ebab17f5c69d2c9ef08aa5fa1426201adfa7e7 /net
parent1a4cedaf65491e66e1e55b8428c89209da729209 (diff)
downloadlinux-linaro-stable-1fd819ecb90cc9b822cd84d3056ddba315d3340f.tar.gz
skbuff: skb_segment: orphan frags before copying
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>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index dc4f7683ff52..869c7afe3b07 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2854,6 +2854,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
skb_frag_t *frag = skb_shinfo(head_skb)->frags;
unsigned int mss = skb_shinfo(head_skb)->gso_size;
unsigned int doffset = head_skb->data - skb_mac_header(head_skb);
+ struct sk_buff *frag_skb = head_skb;
unsigned int offset = doffset;
unsigned int tnl_hlen = skb_tnl_header_len(head_skb);
unsigned int headroom;
@@ -2898,6 +2899,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
i = 0;
nfrags = skb_shinfo(list_skb)->nr_frags;
frag = skb_shinfo(list_skb)->frags;
+ frag_skb = list_skb;
pos += skb_headlen(list_skb);
while (pos < offset + len) {
@@ -2985,6 +2987,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
i = 0;
nfrags = skb_shinfo(list_skb)->nr_frags;
frag = skb_shinfo(list_skb)->frags;
+ frag_skb = list_skb;
BUG_ON(!nfrags);
@@ -2999,6 +3002,9 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
goto err;
}
+ if (unlikely(skb_orphan_frags(frag_skb, GFP_ATOMIC)))
+ goto err;
+
*nskb_frag = *frag;
__skb_frag_ref(nskb_frag);
size = skb_frag_size(nskb_frag);