X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=security%2Fselinux%2Fhooks.c;h=29e64d4ca099511520b8e5b8cf0af83255c52473;hb=b10778a00d40b3d9fdaaf5891e802794781ff71c;hp=b0e940497e23bb47a0460e57a65952f2b4dc7e03;hpb=c6ff6486e5b306f76bf60b0dbfc63a6ed70d0a78;p=firefly-linux-kernel-4.4.55.git diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b0e940497e23..29e64d4ca099 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); @@ -4272,15 +4307,15 @@ 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, @@ -4373,8 +4408,8 @@ 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; @@ -4692,10 +4727,9 @@ 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; } @@ -4713,7 +4747,8 @@ 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; @@ -4739,14 +4774,14 @@ 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; @@ -4775,7 +4810,7 @@ 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) @@ -4785,7 +4820,7 @@ 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 */ @@ -4873,11 +4908,13 @@ 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,}; @@ -4958,6 +4995,7 @@ 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); } @@ -4989,7 +5027,7 @@ 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)) @@ -5011,7 +5049,7 @@ 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) @@ -5021,7 +5059,7 @@ 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 */ @@ -6035,7 +6073,7 @@ 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, @@ -6056,12 +6094,8 @@ 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, @@ -6075,32 +6109,24 @@ 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); @@ -6110,10 +6136,7 @@ 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