xfrm_user: return error pointer instead of NULL #2
diff mbox series

Message ID 1347652712-14584-1-git-send-email-minipli@googlemail.com
State New, archived
Headers show
Series
  • xfrm_user: return error pointer instead of NULL #2
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Commit Message

Mathias Krause Sept. 14, 2012, 7:58 p.m. UTC
When dump_one_policy() returns an error, e.g. because of a too small
buffer to dump the whole xfrm policy, xfrm_policy_netlink() returns
NULL instead of an error pointer. But its caller expects an error
pointer and therefore continues to operate on a NULL skbuff.

Cc: stable@vger.kernel.org
Signed-off-by: Mathias Krause <minipli@googlemail.com>
---

Note, this is a different, but similar issue as my previous patch
with the almost same subject.

I'm not aware of a way how to exploit this bug as the policy *should*
always fit into the netlink buffer but better safe then sorry, so cc
stable.

 net/xfrm/xfrm_user.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Steffen Klassert Sept. 17, 2012, 7:18 a.m. UTC | #1
On Fri, Sep 14, 2012 at 09:58:32PM +0200, Mathias Krause wrote:
> When dump_one_policy() returns an error, e.g. because of a too small
> buffer to dump the whole xfrm policy, xfrm_policy_netlink() returns
> NULL instead of an error pointer. But its caller expects an error
> pointer and therefore continues to operate on a NULL skbuff.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Mathias Krause <minipli@googlemail.com>

Acked-by: Steffen Klassert <steffen.klassert@secunet.com>

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David Miller Sept. 18, 2012, 8:16 p.m. UTC | #2
From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Mon, 17 Sep 2012 09:18:53 +0200

> On Fri, Sep 14, 2012 at 09:58:32PM +0200, Mathias Krause wrote:
>> When dump_one_policy() returns an error, e.g. because of a too small
>> buffer to dump the whole xfrm policy, xfrm_policy_netlink() returns
>> NULL instead of an error pointer. But its caller expects an error
>> pointer and therefore continues to operate on a NULL skbuff.
>> 
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Mathias Krause <minipli@googlemail.com>
> 
> Acked-by: Steffen Klassert <steffen.klassert@secunet.com>

Applied and queued up for -stable.

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Patch
diff mbox series

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index dac08e2..d12b625 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1548,6 +1548,7 @@  static struct sk_buff *xfrm_policy_netlink(struct sk_buff *in_skb,
 {
 	struct xfrm_dump_info info;
 	struct sk_buff *skb;
+	int err;
 
 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!skb)
@@ -1558,9 +1559,10 @@  static struct sk_buff *xfrm_policy_netlink(struct sk_buff *in_skb,
 	info.nlmsg_seq = seq;
 	info.nlmsg_flags = 0;
 
-	if (dump_one_policy(xp, dir, 0, &info) < 0) {
+	err = dump_one_policy(xp, dir, 0, &info);
+	if (err) {
 		kfree_skb(skb);
-		return NULL;
+		return ERR_PTR(err);
 	}
 
 	return skb;