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* [patch] net/key/af_key.c: add range checks on ->sadb_x_policy_len
@ 2012-09-28  8:21 Dan Carpenter
  2012-10-01 21:15 ` David Miller
  0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2012-09-28  8:21 UTC (permalink / raw)
  To: David S. Miller
  Cc: Eric W. Biederman, Eric Dumazet, Stephen Hemminger, netdev,
	kernel-janitors

Because sizeof() is size_t then if "len" is negative, it counts as a
large positive value.

The call tree looks like:
pfkey_sendmsg()
-> pfkey_process()
   -> pfkey_spdadd()
      -> parse_ipsecrequests()

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This is a static checker fix.  I'm not very familiar with this code.
I think if we were to hit this then we would try to parse invalid data
and it would return -EINVAL or similar error code pretty quickly.

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 2ca7d7f..7714df0 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1923,6 +1923,9 @@ parse_ipsecrequests(struct xfrm_policy *xp, struct sadb_x_policy *pol)
 	int len = pol->sadb_x_policy_len*8 - sizeof(struct sadb_x_policy);
 	struct sadb_x_ipsecrequest *rq = (void*)(pol+1);
 
+	if (pol->sadb_x_policy_len * 8 < sizeof(struct sadb_x_policy))
+		return -EINVAL;
+
 	while (len >= sizeof(struct sadb_x_ipsecrequest)) {
 		if ((err = parse_ipsecrequest(xp, rq)) < 0)
 			return err;

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [patch] net/key/af_key.c: add range checks on ->sadb_x_policy_len
  2012-09-28  8:21 [patch] net/key/af_key.c: add range checks on ->sadb_x_policy_len Dan Carpenter
@ 2012-10-01 21:15 ` David Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2012-10-01 21:15 UTC (permalink / raw)
  To: dan.carpenter; +Cc: ebiederm, eric.dumazet, shemminger, netdev, kernel-janitors

From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 28 Sep 2012 11:21:19 +0300

> Because sizeof() is size_t then if "len" is negative, it counts as a
> large positive value.
> 
> The call tree looks like:
> pfkey_sendmsg()
> -> pfkey_process()
>    -> pfkey_spdadd()
>       -> parse_ipsecrequests()
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> This is a static checker fix.  I'm not very familiar with this code.
> I think if we were to hit this then we would try to parse invalid data
> and it would return -EINVAL or similar error code pretty quickly.

Applied and queued up for -stable, thanks Dan.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2012-09-28  8:21 [patch] net/key/af_key.c: add range checks on ->sadb_x_policy_len Dan Carpenter
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