From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
[ Upstream commit 1fd819ecb90cc9b822cd84d3056ddba315d3340f ]
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@xxxxxxxxxx>
Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/core/skbuff.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index a12e7da7c7bc..5a60953e6f39 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2731,6 +2731,7 @@ 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;
@@ -2775,6 +2776,7 @@ 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) {
@@ -2869,6 +2871,7 @@ 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);
@@ -2883,6 +2886,9 @@ 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);
--
2.0.0
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html