From: Jarek Poplawski <jarkao2@gmail.com>
Date: Wed, 11 Aug 2010 02:02:10 +0000 (+0000)
Subject: net: Fix a memmove bug in dev_gro_receive()
X-Git-Tag: firefly_0821_release~10186^2~1080
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=28917a028093cb576b65bcce852b2d9477c2eb7c;p=firefly-linux-kernel-4.4.55.git

net: Fix a memmove bug in dev_gro_receive()

[ Upstream commit e5093aec2e6b60c3df2420057ffab9ed4a6d2792 ]

>Xin Xiaohui wrote:
> I looked into the code dev_gro_receive(), found the code here:
> if the frags[0] is pulled to 0, then the page will be released,
> and memmove() frags left.
> Is that right? I'm not sure if memmove do right or not, but
> frags[0].size is never set after memove at least. what I think
> a simple way is not to do anything if we found frags[0].size == 0.
> The patch is as followed.
...

This version of the patch fixes the bug directly in memmove.

Reported-by: "Xin, Xiaohui" <xiaohui.xin@intel.com>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index 74d0ccef22df..915d0aeb4616 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2519,7 +2519,7 @@ pull:
 			put_page(skb_shinfo(skb)->frags[0].page);
 			memmove(skb_shinfo(skb)->frags,
 				skb_shinfo(skb)->frags + 1,
-				--skb_shinfo(skb)->nr_frags);
+				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
 		}
 	}