Re: BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
From: Justin P. Mattock
Date: Wed Jun 23 2010 - 14:21:21 EST
On 06/23/10 11:10, Timo TerÃs wrote:
On 06/23/2010 08:29 PM, Eric Dumazet wrote:
Le mercredi 23 juin 2010 Ã 10:00 -0700, Justin P. Mattock a Ãcrit :
o.k. the bisect is pointing to the below results..
(I tried git revert xxx but this commit is too big
so I'll(hopefully)manually revert it on the latest HEAD to
see if this is the actual problem im experiencing)
80c802f3073e84c956846e921e8a0b02dfa3755f is the first bad commit
commit 80c802f3073e84c956846e921e8a0b02dfa3755f
Author: Timo TerÃÂs<timo.teras@xxxxxx>
Date: Wed Apr 7 00:30:05 2010 +0000
xfrm: cache bundles instead of policies for outgoing flows
__xfrm_lookup() is called for each packet transmitted out of
system. The xfrm_find_bundle() does a linear search which can
kill system performance depending on how many bundles are
required per policy.
This modifies __xfrm_lookup() to store bundles directly in
the flow cache. If we did not get a hit, we just create a new
bundle instead of doing slow search. This means that we can now
get multiple xfrm_dst's for same flow (on per-cpu basis).
Signed-off-by: Timo Teras<timo.teras@xxxxxx>
Signed-off-by: David S. Miller<davem@xxxxxxxxxxxxx>
:040000 040000 d8e60f5fa4c1329f450d9c7cdf98b34e6a177f22
9f576e68e5bf4ce357d7f0305aee5f410250dfe2 M include
:040000 040000 f2876df688ee36907af7b4123eea96592faaed3e
a3f6f6f94f0309106856cd99b38ec90b024eb016 M net
Thanks a lot for bisecting Jutin, this is really appreciated.
crash is in xfrm_bundle_ok()
if (xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
return 0;
xdst->pols[0] contains a NULL pointer
That does not really make sense, if we get this far; there's a valid
xfrm_state with the bundle. This means that there existed a policy with
it too.
I'll take a deeper look at this tomorrow. Would it be possible to see
your xfrm policies?
- Timo
@Eric sure no problem doing the bisect...
as for the xfrm policy here is the link that I used to setup ipsec:
http://www.linuxfromscratch.org/hints/downloads/files/ipsec.txt
(just change the keys if doing real world work..(but for me just testing).
below is a temporary fix for me to get this working, tcpdump reports
everything is doing what it should be
11:16:32.496166 IP xxxxx > xxxxx: AH(spi=0x00000200,seq=0x1090):
ESP(spi=0x00000201,seq=0x1090), length 56
11:16:32.496212 IP xxxxx > xxxxx: AH(spi=0x00000200,seq=0x1091):
ESP(spi=0x00000201,seq=0x1091), length 56
11:16:32.496259 IP xxxxx > xxxxx: AH(spi=0x00000200,seq=0x1092):
ESP(spi=0x00000201,seq=0x1092), length 56
(tested a few mins ago, but not the right fix..)
From a280d9048c8f8f5756f9f0dcc608b4499645593e Mon Sep 17 00:00:00 2001
From: Justin P. Mattock <justinmattock@xxxxxxxxx>
Date: Wed, 23 Jun 2010 11:10:28 -0700
Subject: [PATCH] fix ipsec
Signed-off-by: Justin P. Mattock <justinmattock@xxxxxxxxx>
---
net/xfrm/xfrm_policy.c | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 4bf27d9..701d69a 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2300,8 +2300,6 @@ int xfrm_bundle_ok(struct xfrm_policy *pol, struct
xfrm_dst *first,
return 0;
if (xdst->xfrm_genid != dst->xfrm->genid)
return 0;
- if (xdst->policy_genid != atomic_read(&xdst->pols[0]->genid))
- return 0;
if (strict && fl &&
!(dst->xfrm->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) &&
--
1.7.1.rc1.21.gf3bd6
I've got the machine ready for any patches.. let me know o.k...
Justin P. Mattock
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