[3.13.y.z extended stable] Patch "net: Move the permission check in sock_diag_put_filterinfo to packet_diag_dump" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    net: Move the permission check in sock_diag_put_filterinfo to packet_diag_dump

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From ea2547714c9c8504e8e0fdd9a4cedae0f3909777 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm at xmission.com>
Date: Wed, 23 Apr 2014 14:26:25 -0700
Subject: net: Move the permission check in sock_diag_put_filterinfo to
 packet_diag_dump

[ Upstream commit a53b72c83a4216f2eb883ed45a0cbce014b8e62d ]

The permission check in sock_diag_put_filterinfo is wrong, and it is so removed
from it's sources it is not clear why it is wrong.  Move the computation
into packet_diag_dump and pass a bool of the result into sock_diag_filterinfo.

This does not yet correct the capability check but instead simply moves it to make
it clear what is going on.

Reported-by: Andy Lutomirski <luto at amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm at xmission.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 include/linux/sock_diag.h | 2 +-
 net/core/sock_diag.c      | 4 ++--
 net/packet/diag.c         | 7 ++++++-
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index 302ab80..46cca4c 100644
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -23,7 +23,7 @@ int sock_diag_check_cookie(void *sk, __u32 *cookie);
 void sock_diag_save_cookie(void *sk, __u32 *cookie);

 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
-int sock_diag_put_filterinfo(struct sock *sk,
+int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
 			     struct sk_buff *skb, int attrtype);

 #endif
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index 6a7fae2..c38e7a2 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -49,7 +49,7 @@ int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
 }
 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);

-int sock_diag_put_filterinfo(struct sock *sk,
+int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
 			     struct sk_buff *skb, int attrtype)
 {
 	struct nlattr *attr;
@@ -57,7 +57,7 @@ int sock_diag_put_filterinfo(struct sock *sk,
 	unsigned int len;
 	int err = 0;

-	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
+	if (!may_report_filterinfo) {
 		nla_reserve(skb, attrtype, 0);
 		return 0;
 	}
diff --git a/net/packet/diag.c b/net/packet/diag.c
index ec8b6e8..01cd1ac 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -127,6 +127,7 @@ static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)

 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
 			struct packet_diag_req *req,
+			bool may_report_filterinfo,
 			struct user_namespace *user_ns,
 			u32 portid, u32 seq, u32 flags, int sk_ino)
 {
@@ -171,7 +172,8 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
 		goto out_nlmsg_trim;

 	if ((req->pdiag_show & PACKET_SHOW_FILTER) &&
-	    sock_diag_put_filterinfo(sk, skb, PACKET_DIAG_FILTER))
+	    sock_diag_put_filterinfo(may_report_filterinfo, sk, skb,
+				     PACKET_DIAG_FILTER))
 		goto out_nlmsg_trim;

 	return nlmsg_end(skb, nlh);
@@ -187,9 +189,11 @@ static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	struct packet_diag_req *req;
 	struct net *net;
 	struct sock *sk;
+	bool may_report_filterinfo;

 	net = sock_net(skb->sk);
 	req = nlmsg_data(cb->nlh);
+	may_report_filterinfo = ns_capable(net->user_ns, CAP_NET_ADMIN);

 	mutex_lock(&net->packet.sklist_lock);
 	sk_for_each(sk, &net->packet.sklist) {
@@ -199,6 +203,7 @@ static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			goto next;

 		if (sk_diag_fill(sk, skb, req,
+				 may_report_filterinfo,
 				 sk_user_ns(NETLINK_CB(cb->skb).sk),
 				 NETLINK_CB(cb->skb).portid,
 				 cb->nlh->nlmsg_seq, NLM_F_MULTI,
--
1.9.1