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Diffstat (limited to 'security/selinux/hooks.c')
-rw-r--r--security/selinux/hooks.c135
1 files changed, 79 insertions, 56 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ada0d0bf3463..8426a2aa8dce 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2097,6 +2097,41 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
/* binprm security operations */
+static int check_nnp_nosuid(const struct linux_binprm *bprm,
+ const struct task_security_struct *old_tsec,
+ const struct task_security_struct *new_tsec)
+{
+ int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
+ int nosuid = (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID);
+ int rc;
+
+ if (!nnp && !nosuid)
+ return 0; /* neither NNP nor nosuid */
+
+ if (new_tsec->sid == old_tsec->sid)
+ return 0; /* No change in credentials */
+
+ /*
+ * The only transitions we permit under NNP or nosuid
+ * are transitions to bounded SIDs, i.e. SIDs that are
+ * guaranteed to only be allowed a subset of the permissions
+ * of the current SID.
+ */
+ rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
+ if (rc) {
+ /*
+ * On failure, preserve the errno values for NNP vs nosuid.
+ * NNP: Operation not permitted for caller.
+ * nosuid: Permission denied to file.
+ */
+ if (nnp)
+ return -EPERM;
+ else
+ return -EACCES;
+ }
+ return 0;
+}
+
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
{
const struct task_security_struct *old_tsec;
@@ -2133,14 +2168,10 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
/* Reset exec SID on execve. */
new_tsec->exec_sid = 0;
- /*
- * Minimize confusion: if no_new_privs or nosuid and a
- * transition is explicitly requested, then fail the exec.
- */
- if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
- return -EPERM;
- if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
- return -EACCES;
+ /* Fail on NNP or nosuid if not an allowed transition. */
+ rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
+ if (rc)
+ return rc;
} else {
/* Check for a default transition on this program. */
rc = security_transition_sid(old_tsec->sid, isec->sid,
@@ -2148,15 +2179,19 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
&new_tsec->sid);
if (rc)
return rc;
+
+ /*
+ * Fallback to old SID on NNP or nosuid if not an allowed
+ * transition.
+ */
+ rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
+ if (rc)
+ new_tsec->sid = old_tsec->sid;
}
ad.type = LSM_AUDIT_DATA_PATH;
ad.u.path = bprm->file->f_path;
- if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
- (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
- new_tsec->sid = old_tsec->sid;
-
if (new_tsec->sid == old_tsec->sid) {
rc = avc_has_perm(old_tsec->sid, isec->sid,
SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
@@ -4270,15 +4305,15 @@ static int selinux_socket_unix_may_send(struct socket *sock,
&ad);
}
-static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
- u32 peer_sid,
+static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
+ char *addrp, u16 family, u32 peer_sid,
struct common_audit_data *ad)
{
int err;
u32 if_sid;
u32 node_sid;
- err = sel_netif_sid(ifindex, &if_sid);
+ err = sel_netif_sid(ns, ifindex, &if_sid);
if (err)
return err;
err = avc_has_perm(peer_sid, if_sid,
@@ -4371,8 +4406,8 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
if (err)
return err;
- err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
- peer_sid, &ad);
+ err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
+ addrp, family, peer_sid, &ad);
if (err) {
selinux_netlbl_err(skb, err, 0);
return err;
@@ -4690,10 +4725,9 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
if (err) {
if (err == -EINVAL) {
- audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
- "SELinux: unrecognized netlink message"
- " type=%hu for sclass=%hu\n",
- nlh->nlmsg_type, sksec->sclass);
+ WARN_ONCE(1, "selinux_nlmsg_perm: unrecognized netlink message:"
+ " protocol=%hu nlmsg_type=%hu sclass=%hu\n",
+ sk->sk_protocol, nlh->nlmsg_type, sksec->sclass);
if (!selinux_enforcing || security_get_allow_unknown())
err = 0;
}
@@ -4711,7 +4745,8 @@ out:
#ifdef CONFIG_NETFILTER
-static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_forward(struct sk_buff *skb,
+ const struct net_device *indev,
u16 family)
{
int err;
@@ -4737,14 +4772,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
ad.type = LSM_AUDIT_DATA_NET;
ad.u.net = &net;
- ad.u.net->netif = ifindex;
+ ad.u.net->netif = indev->ifindex;
ad.u.net->family = family;
if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
return NF_DROP;
if (peerlbl_active) {
- err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
- peer_sid, &ad);
+ err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
+ addrp, family, peer_sid, &ad);
if (err) {
selinux_netlbl_err(skb, err, 1);
return NF_DROP;
@@ -4773,7 +4808,7 @@ static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
- return selinux_ip_forward(skb, in->ifindex, PF_INET);
+ return selinux_ip_forward(skb, in, PF_INET);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -4783,7 +4818,7 @@ static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
- return selinux_ip_forward(skb, in->ifindex, PF_INET6);
+ return selinux_ip_forward(skb, in, PF_INET6);
}
#endif /* IPV6 */
@@ -4871,11 +4906,13 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
return NF_ACCEPT;
}
-static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_postroute(struct sk_buff *skb,
+ const struct net_device *outdev,
u16 family)
{
u32 secmark_perm;
u32 peer_sid;
+ int ifindex = outdev->ifindex;
struct sock *sk;
struct common_audit_data ad;
struct lsm_network_audit net = {0,};
@@ -4956,6 +4993,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
case PF_INET6:
if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
return NF_ACCEPT;
+ break;
default:
return NF_DROP_ERR(-ECONNREFUSED);
}
@@ -4987,7 +5025,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
u32 if_sid;
u32 node_sid;
- if (sel_netif_sid(ifindex, &if_sid))
+ if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
return NF_DROP;
if (avc_has_perm(peer_sid, if_sid,
SECCLASS_NETIF, NETIF__EGRESS, &ad))
@@ -5009,7 +5047,7 @@ static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
- return selinux_ip_postroute(skb, out->ifindex, PF_INET);
+ return selinux_ip_postroute(skb, out, PF_INET);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -5019,7 +5057,7 @@ static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
- return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
+ return selinux_ip_postroute(skb, out, PF_INET6);
}
#endif /* IPV6 */
@@ -6033,7 +6071,7 @@ security_initcall(selinux_init);
#if defined(CONFIG_NETFILTER)
-static struct nf_hook_ops selinux_ipv4_ops[] = {
+static struct nf_hook_ops selinux_nf_ops[] = {
{
.hook = selinux_ipv4_postroute,
.owner = THIS_MODULE,
@@ -6054,12 +6092,8 @@ static struct nf_hook_ops selinux_ipv4_ops[] = {
.pf = NFPROTO_IPV4,
.hooknum = NF_INET_LOCAL_OUT,
.priority = NF_IP_PRI_SELINUX_FIRST,
- }
-};
-
+ },
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-
-static struct nf_hook_ops selinux_ipv6_ops[] = {
{
.hook = selinux_ipv6_postroute,
.owner = THIS_MODULE,
@@ -6073,32 +6107,24 @@ static struct nf_hook_ops selinux_ipv6_ops[] = {
.pf = NFPROTO_IPV6,
.hooknum = NF_INET_FORWARD,
.priority = NF_IP6_PRI_SELINUX_FIRST,
- }
-};
-
+ },
#endif /* IPV6 */
+};
static int __init selinux_nf_ip_init(void)
{
- int err = 0;
+ int err;
if (!selinux_enabled)
- goto out;
+ return 0;
printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n");
- err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
+ err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
if (err)
- panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
+ panic("SELinux: nf_register_hooks: error %d\n", err);
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
- err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
- if (err)
- panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
-#endif /* IPV6 */
-
-out:
- return err;
+ return 0;
}
__initcall(selinux_nf_ip_init);
@@ -6108,10 +6134,7 @@ static void selinux_nf_ip_exit(void)
{
printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n");
- nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
- nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
-#endif /* IPV6 */
+ nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
}
#endif