[NETLINK]: Encapsulate eff_cap usage within security framework.
This patch encapsulates the usage of eff_cap (in netlink_skb_params) within
the security framework by extending security_netlink_recv to include a required
capability parameter and converting all direct usage of eff_caps outside
of the lsm modules to use the interface. It also updates the SELinux
implementation of the security_netlink_send and security_netlink_recv
hooks to take advantage of the sid in the netlink_skb_params struct.
This also enables SELinux to perform auditing of netlink capability checks.
Please apply, for 2.6.18 if possible.
Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/security.h b/include/linux/security.h
index 5180580..c7ea157 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -67,7 +67,7 @@
struct xfrm_user_sec_ctx;
extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
-extern int cap_netlink_recv(struct sk_buff *skb);
+extern int cap_netlink_recv(struct sk_buff *skb, int cap);
/*
* Values used in the task_security_ops calls
@@ -656,6 +656,7 @@
* Check permission before processing the received netlink message in
* @skb.
* @skb contains the sk_buff structure for the netlink message.
+ * @cap indicates the capability required
* Return 0 if permission is granted.
*
* Security hooks for Unix domain networking.
@@ -1266,7 +1267,7 @@
struct sembuf * sops, unsigned nsops, int alter);
int (*netlink_send) (struct sock * sk, struct sk_buff * skb);
- int (*netlink_recv) (struct sk_buff * skb);
+ int (*netlink_recv) (struct sk_buff * skb, int cap);
/* allow module stacking */
int (*register_security) (const char *name,
@@ -2032,9 +2033,9 @@
return security_ops->netlink_send(sk, skb);
}
-static inline int security_netlink_recv(struct sk_buff * skb)
+static inline int security_netlink_recv(struct sk_buff * skb, int cap)
{
- return security_ops->netlink_recv(skb);
+ return security_ops->netlink_recv(skb, cap);
}
/* prototypes */
@@ -2670,9 +2671,9 @@
return cap_netlink_send (sk, skb);
}
-static inline int security_netlink_recv (struct sk_buff *skb)
+static inline int security_netlink_recv (struct sk_buff *skb, int cap)
{
- return cap_netlink_recv (skb);
+ return cap_netlink_recv (skb, cap);
}
static inline struct dentry *securityfs_create_dir(const char *name,
diff --git a/kernel/audit.c b/kernel/audit.c
index 82443fb..d417ca1 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -445,7 +445,7 @@
* Check for appropriate CAP_AUDIT_ capabilities on incoming audit
* control messages.
*/
-static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type)
+static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
{
int err = 0;
@@ -459,13 +459,13 @@
case AUDIT_DEL:
case AUDIT_DEL_RULE:
case AUDIT_SIGNAL_INFO:
- if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL))
+ if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
err = -EPERM;
break;
case AUDIT_USER:
case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
- if (!cap_raised(eff_cap, CAP_AUDIT_WRITE))
+ if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
err = -EPERM;
break;
default: /* bad msg */
@@ -488,7 +488,7 @@
char *ctx;
u32 len;
- err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
+ err = audit_netlink_ok(skb, msg_type);
if (err)
return err;
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 3fcfa9c..f25aac1 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -663,7 +663,7 @@
sz_idx = type>>2;
kind = type&3;
- if (kind != 2 && security_netlink_recv(skb)) {
+ if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN)) {
*errp = -EPERM;
return -1;
}
diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index 74133ec..8b99bd3 100644
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -107,7 +107,7 @@
if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
return;
- if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
+ if (security_netlink_recv(skb, CAP_NET_ADMIN))
RCV_SKB_FAIL(-EPERM);
/* Eventually we might send routing messages too */
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 213d116..198ac36 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -515,7 +515,7 @@
if (type <= IPQM_BASE)
return;
- if (security_netlink_recv(skb))
+ if (security_netlink_recv(skb, CAP_NET_ADMIN))
RCV_SKB_FAIL(-EPERM);
write_lock_bh(&queue_lock);
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index b4b7d44..968a14b 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -505,7 +505,7 @@
if (type <= IPQM_BASE)
return;
- if (security_netlink_recv(skb))
+ if (security_netlink_recv(skb, CAP_NET_ADMIN))
RCV_SKB_FAIL(-EPERM);
write_lock_bh(&queue_lock);
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index b88e82a..ec9f0ef 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -229,7 +229,7 @@
NFNL_SUBSYS_ID(nlh->nlmsg_type),
NFNL_MSG_TYPE(nlh->nlmsg_type));
- if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN)) {
+ if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
DEBUGP("missing CAP_NET_ADMIN\n");
*errp = -EPERM;
return -1;
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index f329b72..edf084b 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -320,7 +320,7 @@
goto errout;
}
- if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb)) {
+ if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb, CAP_NET_ADMIN)) {
err = -EPERM;
goto errout;
}
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index c21dc26..3e6a722 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1435,7 +1435,7 @@
link = &xfrm_dispatch[type];
/* All operations require privileges, even GET */
- if (security_netlink_recv(skb)) {
+ if (security_netlink_recv(skb, CAP_NET_ADMIN)) {
*errp = -EPERM;
return -1;
}
diff --git a/security/commoncap.c b/security/commoncap.c
index 841eb4e..57673ee 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -33,9 +33,9 @@
EXPORT_SYMBOL(cap_netlink_send);
-int cap_netlink_recv(struct sk_buff *skb)
+int cap_netlink_recv(struct sk_buff *skb, int cap)
{
- if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
+ if (!cap_raised(NETLINK_CB(skb).eff_cap, cap))
return -EPERM;
return 0;
}
diff --git a/security/dummy.c b/security/dummy.c
index 310fcdf7..9135408 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -675,9 +675,9 @@
return 0;
}
-static int dummy_netlink_recv (struct sk_buff *skb)
+static int dummy_netlink_recv (struct sk_buff *skb, int cap)
{
- if (!cap_raised (NETLINK_CB (skb).eff_cap, CAP_NET_ADMIN))
+ if (!cap_raised (NETLINK_CB (skb).eff_cap, cap))
return -EPERM;
return 0;
}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 28832e6..b6c378d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3641,32 +3641,32 @@
static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
- struct task_security_struct *tsec;
- struct av_decision avd;
int err;
err = secondary_ops->netlink_send(sk, skb);
if (err)
return err;
- tsec = current->security;
-
- avd.allowed = 0;
- avc_has_perm_noaudit(tsec->sid, tsec->sid,
- SECCLASS_CAPABILITY, ~0, &avd);
- cap_mask(NETLINK_CB(skb).eff_cap, avd.allowed);
-
if (policydb_loaded_version >= POLICYDB_VERSION_NLCLASS)
err = selinux_nlmsg_perm(sk, skb);
return err;
}
-static int selinux_netlink_recv(struct sk_buff *skb)
+static int selinux_netlink_recv(struct sk_buff *skb, int capability)
{
- if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
- return -EPERM;
- return 0;
+ int err;
+ struct avc_audit_data ad;
+
+ err = secondary_ops->netlink_recv(skb, capability);
+ if (err)
+ return err;
+
+ AVC_AUDIT_DATA_INIT(&ad, CAP);
+ ad.u.cap = capability;
+
+ return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
+ SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
}
static int ipc_alloc_security(struct task_struct *task,