[188/244] xfrm: Perform a replay check after return from async codepaths

From: Greg KH
Date: Wed Sep 28 2011 - 18:49:54 EST


3.0-stable review patch. If anyone has any objections, please let us know.

------------------


From: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>

[ Upstream commit bcf66bf54aabffc150acd1c99e0f4bc51935eada ]

When asyncronous crypto algorithms are used, there might be many
packets that passed the xfrm replay check, but the replay advance
function is not called yet for these packets. So the replay check
function would accept a replay of all of these packets. Also the
system might crash if there are more packets in async processing
than the size of the anti replay window, because the replay advance
function would try to update the replay window beyond the bounds.

This pach adds a second replay check after resuming from the async
processing to fix these issues.

Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Acked-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
net/xfrm/xfrm_input.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -212,6 +212,11 @@ resume:
/* only the first xfrm gets the encap type */
encap_type = 0;

+ if (async && x->repl->check(x, skb, seq)) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
+ goto drop_unlock;
+ }
+
x->repl->advance(x, seq);

x->curlft.bytes += skb->len;


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