[Non-DoD Source] [PATCH 07/11] LSM: Shared secids by token
Stephen Smalley
sds at tycho.nsa.gov
Thu Aug 31 16:30:21 UTC 2017
On Tue, 2017-08-29 at 14:01 -0700, Casey Schaufler wrote:
> Subject: [PATCH 07/11] LSM: Shared secids by token
>
> Introduces a mechanism for mapping a set of security
> module secids to and from a "token". The module interfaces
> are changed to generally hide the mechanism from both the
> security modules and the callers of the security hooks.
>
> Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
> ---
> include/linux/lsm_hooks.h | 54 ++++++++-
> security/Makefile | 1 +
> security/security.c | 248
> ++++++++++++++++++++++++++++++++++-----
> security/selinux/hooks.c | 31 +++--
> security/selinux/include/xfrm.h | 2 +-
> security/selinux/xfrm.c | 6 +-
> security/smack/smack.h | 1 +
> security/smack/smack_lsm.c | 19 ++-
> security/smack/smack_netfilter.c | 17 ++-
> security/stacking.c | 165 ++++++++++++++++++++++++++
> 10 files changed, 497 insertions(+), 47 deletions(-)
> create mode 100644 security/stacking.c
>
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index dfe4dab1ff8d..75d95854f2ed 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -1627,7 +1627,7 @@ union security_list_options {
> void (*secmark_refcount_inc)(void);
> void (*secmark_refcount_dec)(void);
> void (*req_classify_flow)(const struct request_sock *req,
> - struct flowi *fl);
> + u32 *fl_secid);
> int (*tun_dev_alloc_security)(void **security);
> void (*tun_dev_free_security)(void *security);
> int (*tun_dev_create)(void);
> @@ -1663,7 +1663,7 @@ union security_list_options {
> u8 dir);
> int (*xfrm_state_pol_flow_match)(struct xfrm_state *x,
> struct xfrm_policy
> *xp,
> - const struct flowi
> *fl);
> + u32 fl_secid);
> int (*xfrm_decode_session)(struct sk_buff *skb, u32 *secid,
> int ckall);
> #endif /* CONFIG_SECURITY_NETWORK_XFRM */
>
> @@ -1916,9 +1916,59 @@ struct security_hook_list {
> struct list_head *head;
> union security_list_options hook;
> char *lsm;
> + int lsm_index;
> } __randomize_layout;
>
> /*
> + * The maximum number of major security modules.
> + * Used to avoid excessive memory management while
> + * mapping global and module specific secids.
> + *
> + * Currently SELinux, Smack, AppArmor, TOMOYO
> + * Oh, but Casey needs to come up with the right way
> + * to identify a "major" module, so use the total number
> + * of modules (including minor) for now.
> + * Minor: Capability, Yama, LoadPin
> + */
> +#define LSM_MAX_MAJOR 8
> +
> +#ifdef CONFIG_SECURITY_STACKING
> +struct lsm_secids {
> + u32 secid[LSM_MAX_MAJOR];
> +};
> +
> +extern u32 lsm_secids_to_token(const struct lsm_secids *secids);
> +extern void lsm_token_to_secids(const u32 token, struct lsm_secids
> *secids);
> +extern u32 lsm_token_to_module_secid(const u32 token, int lsm);
> +extern void lsm_secids_init(struct lsm_secids *secids);
> +#else /* CONFIG_SECURITY_STACKING */
> +struct lsm_secids {
> + u32 secid;
> +};
> +
> +static inline u32 lsm_secids_to_token(const struct lsm_secids
> *secids)
> +{
> + return secids->secid;
> +}
> +
> +static inline void lsm_token_to_secids(const u32 token,
> + struct lsm_secids *secids)
> +{
> + secids->secid = token;
> +}
> +
> +static inline u32 lsm_token_to_module_secid(const u32 token, int
> lsm)
> +{
> + return token;
> +}
> +
> +static inline void lsm_secids_init(struct lsm_secids *secids)
> +{
> + secids->secid = 0;
> +}
> +#endif /* CONFIG_SECURITY_STACKING */
> +
> +/*
> * Security blob size or offset data.
> */
> struct lsm_blob_sizes {
> diff --git a/security/Makefile b/security/Makefile
> index f2d71cdb8e19..05e6d525b5a1 100644
> --- a/security/Makefile
> +++ b/security/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_SECURITY_APPARMOR) +=
> apparmor/
> obj-$(CONFIG_SECURITY_YAMA) += yama/
> obj-$(CONFIG_SECURITY_LOADPIN) += loadpin/
> obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o
> +obj-$(CONFIG_SECURITY_STACKING) += stacking.o
>
> # Object integrity file lists
> subdir-$(CONFIG_INTEGRITY) += integrity
> diff --git a/security/security.c b/security/security.c
> index 6b979aa769ad..9d402d954cef 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -199,6 +199,11 @@ bool __init security_module_enable(const char
> *lsm, const bool stacked)
> #endif
> }
>
> +/*
> + * Keep the order of major modules for mapping secids.
> + */
> +static int lsm_next_major;
> +
> /**
> * security_add_hooks - Add a modules hooks to the hook lists.
> * @hooks: the hooks to add
> @@ -211,9 +216,14 @@ void __init security_add_hooks(struct
> security_hook_list *hooks, int count,
> char *lsm)
> {
> int i;
> + int lsm_index = lsm_next_major++;
>
> +#ifdef CONFIG_SECURITY_LSM_DEBUG
> + pr_info("LSM: Security module %s gets index %d\n", lsm,
> lsm_index);
> +#endif
> for (i = 0; i < count; i++) {
> hooks[i].lsm = lsm;
> + hooks[i].lsm_index = lsm_index;
> list_add_tail_rcu(&hooks[i].list, hooks[i].head);
> }
> if (lsm_append(lsm, &lsm_names) < 0)
> @@ -1218,7 +1228,15 @@ EXPORT_SYMBOL(security_inode_listsecurity);
>
> void security_inode_getsecid(struct inode *inode, u32 *secid)
> {
> - call_void_hook(inode_getsecid, inode, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.inode_getsecid,
> list)
> + hp->hook.inode_getsecid(inode, &secids.secid[hp-
> >lsm_index]);
> +
> + *secid = lsm_secids_to_token(&secids);
> }
>
> int security_inode_copy_up(struct dentry *src, struct cred **new)
> @@ -1406,7 +1424,18 @@ void security_transfer_creds(struct cred *new,
> const struct cred *old)
>
> int security_kernel_act_as(struct cred *new, u32 secid)
> {
> - return call_int_hook(kernel_act_as, 0, new, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.kernel_act_as,
> list) {
> + rc = hp->hook.kernel_act_as(new, secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> + return rc;
> }
>
> int security_kernel_create_files_as(struct cred *new, struct inode
> *inode)
> @@ -1465,8 +1494,15 @@ int security_task_getsid(struct task_struct
> *p)
>
> void security_task_getsecid(struct task_struct *p, u32 *secid)
> {
> - *secid = 0;
> - call_void_hook(task_getsecid, p, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.task_getsecid,
> list)
> + hp->hook.task_getsecid(p, &secids.secid[hp-
> >lsm_index]);
> +
> + *secid = lsm_secids_to_token(&secids);
> }
> EXPORT_SYMBOL(security_task_getsecid);
>
> @@ -1515,7 +1551,19 @@ int security_task_movememory(struct
> task_struct *p)
> int security_task_kill(struct task_struct *p, struct siginfo *info,
> int sig, u32 secid)
> {
> - return call_int_hook(task_kill, 0, p, info, sig, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.task_kill,
> list) {
> + rc = hp->hook.task_kill(p, info, sig,
> + secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> + return rc;
> }
>
> int security_task_prctl(int option, unsigned long arg2, unsigned
> long arg3,
> @@ -1548,8 +1596,15 @@ int security_ipc_permission(struct
> kern_ipc_perm *ipcp, short flag)
>
> void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> {
> - *secid = 0;
> - call_void_hook(ipc_getsecid, ipcp, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.ipc_getsecid,
> list)
> + hp->hook.ipc_getsecid(ipcp, &secids.secid[hp-
> >lsm_index]);
> +
> + *secid = lsm_secids_to_token(&secids);
> }
>
> int security_msg_msg_alloc(struct msg_msg *msg)
> @@ -1840,15 +1895,42 @@ EXPORT_SYMBOL(security_ismaclabel);
>
> int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> {
> - return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid,
> secdata,
> - seclen);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = -EOPNOTSUPP;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + /*
> + * CBS - Return the first result regardless.
> + */
> + list_for_each_entry(hp,
> &security_hook_heads.secid_to_secctx, list) {
> + rc = hp->hook.secid_to_secctx(secids.secid[hp-
> >lsm_index],
> + secdata, seclen);
> + if (rc != -EOPNOTSUPP)
> + break;
> + }
> + return rc;
> }
> EXPORT_SYMBOL(security_secid_to_secctx);
>
> int security_secctx_to_secid(const char *secdata, u32 seclen, u32
> *secid)
> {
> - *secid = 0;
> - return call_int_hook(secctx_to_secid, 0, secdata, seclen,
> secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.secctx_to_secid, list) {
> + rc = hp->hook.secctx_to_secid(secdata, seclen,
> + &secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> +
> + *secid = lsm_secids_to_token(&secids);
> + return rc;
> }
> EXPORT_SYMBOL(security_secctx_to_secid);
>
> @@ -1977,10 +2059,26 @@ int security_socket_getpeersec_stream(struct
> socket *sock, char __user *optval,
> optval, optlen, len);
> }
>
> -int security_socket_getpeersec_dgram(struct socket *sock, struct
> sk_buff *skb, u32 *secid)
> +int security_socket_getpeersec_dgram(struct socket *sock, struct
> sk_buff *skb,
> + u32 *secid)
> {
> - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT,
> sock,
> - skb, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = -ENOPROTOOPT;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.socket_getpeersec_dgram,
> +
> list) {
> + rc = hp->hook.socket_getpeersec_dgram(sock, skb,
> + &secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> +
> + if (!rc)
> + *secid = lsm_secids_to_token(&secids);
> + return rc;
> }
> EXPORT_SYMBOL(security_socket_getpeersec_dgram);
>
> @@ -2008,13 +2106,30 @@ EXPORT_SYMBOL(security_sk_clone);
>
> void security_sk_classify_flow(struct sock *sk, struct flowi *fl)
> {
> - call_void_hook(sk_getsecid, sk, &fl->flowi_secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp, &security_hook_heads.sk_getsecid,
> list)
> + hp->hook.sk_getsecid(sk, &secids.secid[hp-
> >lsm_index]);
> +
> + fl->flowi_secid = lsm_secids_to_token(&secids);
> }
> EXPORT_SYMBOL(security_sk_classify_flow);
>
> -void security_req_classify_flow(const struct request_sock *req,
> struct flowi *fl)
> +void security_req_classify_flow(const struct request_sock *req,
> + struct flowi *fl)
> {
> - call_void_hook(req_classify_flow, req, fl);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.req_classify_flow, list)
> + hp->hook.req_classify_flow(req, &secids.secid[hp-
> >lsm_index]);
> +
> + fl->flowi_secid = lsm_secids_to_token(&secids);
> }
> EXPORT_SYMBOL(security_req_classify_flow);
>
> @@ -2045,7 +2160,20 @@ void security_inet_conn_established(struct
> sock *sk,
>
> int security_secmark_relabel_packet(u32 secid)
> {
> - return call_int_hook(secmark_relabel_packet, 0, secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.secmark_relabel_packet,
> +
> list) {
> + rc = hp->hook.secmark_relabel_packet(
> + secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> + return rc;
> }
> EXPORT_SYMBOL(security_secmark_relabel_packet);
>
> @@ -2163,7 +2291,20 @@ EXPORT_SYMBOL(security_xfrm_state_alloc);
> int security_xfrm_state_alloc_acquire(struct xfrm_state *x,
> struct xfrm_sec_ctx *polsec,
> u32 secid)
> {
> - return call_int_hook(xfrm_state_alloc_acquire, 0, x, polsec,
> secid);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.xfrm_state_alloc_acquire,
> +
> list) {
> + rc = hp->hook.xfrm_state_alloc_acquire(x, polsec,
> + secids.secid[hp-
> >lsm_index]);
> + if (rc)
> + break;
> + }
> + return rc;
> }
>
> int security_xfrm_state_delete(struct xfrm_state *x)
> @@ -2179,7 +2320,19 @@ void security_xfrm_state_free(struct
> xfrm_state *x)
>
> int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32
> fl_secid, u8 dir)
> {
> - return call_int_hook(xfrm_policy_lookup, 0, ctx, fl_secid,
> dir);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(fl_secid, &secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.xfrm_policy_lookup, list) {
> + rc = hp->hook.xfrm_policy_lookup(ctx,
> + secids.secid[hp->lsm_index],
> dir);
> + if (rc)
> + break;
> + }
> + return rc;
> }
>
> int security_xfrm_state_pol_flow_match(struct xfrm_state *x,
> @@ -2187,6 +2340,7 @@ int security_xfrm_state_pol_flow_match(struct
> xfrm_state *x,
> const struct flowi *fl)
> {
> struct security_hook_list *hp;
> + struct lsm_secids secids;
> int rc = 1;
>
> /*
> @@ -2198,9 +2352,12 @@ int security_xfrm_state_pol_flow_match(struct
> xfrm_state *x,
> * For speed optimization, we explicitly break the loop
> rather than
> * using the macro
> */
> + lsm_token_to_secids(fl->flowi_secid, &secids);
> +
> list_for_each_entry(hp,
> &security_hook_heads.xfrm_state_pol_flow_match,
> - list) {
> - rc = hp->hook.xfrm_state_pol_flow_match(x, xp, fl);
> +
> list) {
> + rc = hp->hook.xfrm_state_pol_flow_match(x, xp,
> + secids.secid[hp->lsm_index]);
> break;
> }
> return rc;
> @@ -2208,15 +2365,41 @@ int security_xfrm_state_pol_flow_match(struct
> xfrm_state *x,
>
> int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid)
> {
> - return call_int_hook(xfrm_decode_session, 0, skb, secid, 1);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_secids_init(&secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.xfrm_decode_session,
> +
> list) {
> + rc = hp->hook.xfrm_decode_session(skb,
> + &secids.secid[hp-
> >lsm_index], 1);
> + if (rc)
> + break;
> + }
> + if (!rc)
> + *secid = lsm_secids_to_token(&secids);
> + return rc;
> }
>
> void security_skb_classify_flow(struct sk_buff *skb, struct flowi
> *fl)
> {
> - int rc = call_int_hook(xfrm_decode_session, 0, skb, &fl-
> >flowi_secid,
> - 0);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_secids_init(&secids);
>
> + list_for_each_entry(hp,
> &security_hook_heads.xfrm_decode_session,
> +
> list) {
> + rc = hp->hook.xfrm_decode_session(skb,
> + &secids.secid[hp-
> >lsm_index], 0);
> + if (rc)
> + break;
> + }
> BUG_ON(rc);
> + fl->flowi_secid = lsm_secids_to_token(&secids);
> }
> EXPORT_SYMBOL(security_skb_classify_flow);
>
> @@ -2275,7 +2458,18 @@ void security_audit_rule_free(void *lsmrule)
> int security_audit_rule_match(u32 secid, u32 field, u32 op, void
> *lsmrule,
> struct audit_context *actx)
> {
> - return call_int_hook(audit_rule_match, 0, secid, field, op,
> lsmrule,
> - actx);
> + struct security_hook_list *hp;
> + struct lsm_secids secids;
> + int rc = 0;
> +
> + lsm_token_to_secids(secid, &secids);
> +
> + list_for_each_entry(hp,
> &security_hook_heads.audit_rule_match, list) {
> + rc = hp->hook.audit_rule_match(secids.secid[hp-
> >lsm_index],
> + field, op, lsmrule,
> actx);
> + if (rc)
> + break;
> + }
> + return rc;
> }
> #endif /* CONFIG_AUDIT */
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 84d533335924..389f09ebd374 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -100,6 +100,9 @@
> /* SECMARK reference count */
> static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
>
> +/* Index into lsm_secids */
> +static int selinux_secids_index;
> +
> #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
> int selinux_enforcing;
>
> @@ -4610,6 +4613,11 @@ static int selinux_inet_sys_rcv_skb(struct net
> *ns, int ifindex,
> SECCLASS_NODE, NODE__RECVFROM, ad);
> }
>
> +static u32 selinux_secmark_to_secid(u32 token)
> +{
> + return lsm_token_to_module_secid(token,
> selinux_secids_index);
> +}
> +
> static int selinux_sock_rcv_skb_compat(struct sock *sk, struct
> sk_buff *skb,
> u16 family)
> {
> @@ -4629,7 +4637,9 @@ static int selinux_sock_rcv_skb_compat(struct
> sock *sk, struct sk_buff *skb,
> return err;
>
> if (selinux_secmark_enabled()) {
> - err = avc_has_perm(sk_sid, skb->secmark,
> SECCLASS_PACKET,
> + err = avc_has_perm(sk_sid,
> + selinux_secmark_to_secid(skb-
> >secmark),
> + SECCLASS_PACKET,
> PACKET__RECV, &ad);
> if (err)
> return err;
> @@ -4703,7 +4713,9 @@ static int selinux_socket_sock_rcv_skb(struct
> sock *sk, struct sk_buff *skb)
> }
>
> if (secmark_active) {
> - err = avc_has_perm(sk_sid, skb->secmark,
> SECCLASS_PACKET,
> + err = avc_has_perm(sk_sid,
> + selinux_secmark_to_secid(skb-
> >secmark),
> + SECCLASS_PACKET,
> PACKET__RECV, &ad);
> if (err)
> return err;
> @@ -4902,9 +4914,9 @@ static void selinux_secmark_refcount_dec(void)
> }
>
> static void selinux_req_classify_flow(const struct request_sock
> *req,
> - struct flowi *fl)
> + u32 *fl_secid)
> {
> - fl->flowi_secid = req->secid;
> + *fl_secid = req->secid;
> }
>
> static int selinux_tun_dev_alloc_security(void **security)
> @@ -5066,7 +5078,8 @@ static unsigned int selinux_ip_forward(struct
> sk_buff *skb,
> }
>
> if (secmark_active)
> - if (avc_has_perm(peer_sid, skb->secmark,
> + if (avc_has_perm(peer_sid,
> + selinux_secmark_to_secid(skb-
> >secmark),
> SECCLASS_PACKET,
> PACKET__FORWARD_IN, &ad))
> return NF_DROP;
>
> @@ -5178,7 +5191,8 @@ static unsigned int
> selinux_ip_postroute_compat(struct sk_buff *skb,
> return NF_DROP;
>
> if (selinux_secmark_enabled())
> - if (avc_has_perm(sksec->sid, skb->secmark,
> + if (avc_has_perm(sksec->sid,
> + selinux_secmark_to_secid(skb-
> >secmark),
> SECCLASS_PACKET, PACKET__SEND,
> &ad))
> return NF_DROP_ERR(-ECONNREFUSED);
>
> @@ -5301,7 +5315,8 @@ static unsigned int selinux_ip_postroute(struct
> sk_buff *skb,
> return NF_DROP;
>
> if (secmark_active)
> - if (avc_has_perm(peer_sid, skb->secmark,
> + if (avc_has_perm(peer_sid,
> + selinux_secmark_to_secid(skb-
> >secmark),
> SECCLASS_PACKET, secmark_perm,
> &ad))
> return NF_DROP_ERR(-ECONNREFUSED);
>
> @@ -6339,6 +6354,8 @@ static __init int selinux_init(void)
>
> security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
> "selinux");
>
> + selinux_secids_index = selinux_hooks[0].lsm_index;
> +
> if (avc_add_callback(selinux_netcache_avc_callback,
> AVC_CALLBACK_RESET))
> panic("SELinux: Unable to register AVC netcache
> callback\n");
>
> diff --git a/security/selinux/include/xfrm.h
> b/security/selinux/include/xfrm.h
> index 1450f85b946d..475a328248b3 100644
> --- a/security/selinux/include/xfrm.h
> +++ b/security/selinux/include/xfrm.h
> @@ -25,7 +25,7 @@ int selinux_xfrm_state_delete(struct xfrm_state
> *x);
> int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32
> fl_secid, u8 dir);
> int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x,
> struct xfrm_policy *xp,
> - const struct flowi *fl);
> + u32 fl_secid);
>
> #ifdef CONFIG_SECURITY_NETWORK_XFRM
> extern atomic_t selinux_xfrm_refcount;
> diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
> index 789d07bd900f..d71e2c32b5da 100644
> --- a/security/selinux/xfrm.c
> +++ b/security/selinux/xfrm.c
> @@ -174,7 +174,7 @@ int selinux_xfrm_policy_lookup(struct
> xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir)
> */
> int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x,
> struct xfrm_policy *xp,
> - const struct flowi *fl)
> + u32 fl_secid)
> {
> u32 state_sid;
>
> @@ -196,13 +196,13 @@ int selinux_xfrm_state_pol_flow_match(struct
> xfrm_state *x,
>
> state_sid = x->security->ctx_sid;
>
> - if (fl->flowi_secid != state_sid)
> + if (fl_secid != state_sid)
> return 0;
>
> /* We don't need a separate SA Vs. policy polmatch check
> since the SA
> * is now of the same label as the flow and a flow Vs.
> policy polmatch
> * check had already happened in
> selinux_xfrm_policy_lookup() above. */
> - return (avc_has_perm(fl->flowi_secid, state_sid,
> + return (avc_has_perm(fl_secid, state_sid,
> SECCLASS_ASSOCIATION,
> ASSOCIATION__SENDTO,
> NULL) ? 0 : 1);
> }
> diff --git a/security/smack/smack.h b/security/smack/smack.h
> index e7611de071f1..e9fd586e0ec1 100644
> --- a/security/smack/smack.h
> +++ b/security/smack/smack.h
> @@ -328,6 +328,7 @@ void smk_destroy_label_list(struct list_head
> *list);
> * Shared data.
> */
> extern int smack_enabled;
> +extern int smack_secids_index;
> extern int smack_cipso_direct;
> extern int smack_cipso_mapped;
> extern struct smack_known *smack_net_ambient;
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 1e9ab7bdaf55..51daf9b05f17 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -57,6 +57,7 @@ static LIST_HEAD(smk_ipv6_port_list);
> #endif
> static struct kmem_cache *smack_inode_cache;
> int smack_enabled;
> +int smack_secids_index;
>
> static const match_table_t smk_mount_tokens = {
> {Opt_fsdefault, SMK_FSDEFAULT "%s"},
> @@ -3788,6 +3789,13 @@ static int smk_skb_to_addr_ipv6(struct sk_buff
> *skb, struct sockaddr_in6 *sip)
> }
> #endif /* CONFIG_IPV6 */
>
> +#ifdef CONFIG_SECURITY_SMACK_NETFILTER
> +static u32 smk_of_secmark(u32 secmark)
> +{
> + return lsm_token_to_module_secid(secmark,
> smack_secids_index);
> +}
> +#endif
> +
> /**
> * smack_socket_sock_rcv_skb - Smack packet delivery access check
> * @sk: socket
> @@ -3819,7 +3827,7 @@ static int smack_socket_sock_rcv_skb(struct
> sock *sk, struct sk_buff *skb)
> * The secmark is assumed to reflect policy better.
> */
> if (skb && skb->secmark != 0) {
> - skp = smack_from_secid(skb->secmark);
> + skp = smack_from_secid(smk_of_secmark(skb-
> >secmark));
> goto access_check;
> }
> #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
> @@ -3864,7 +3872,7 @@ static int smack_socket_sock_rcv_skb(struct
> sock *sk, struct sk_buff *skb)
> break;
> #ifdef SMACK_IPV6_SECMARK_LABELING
> if (skb && skb->secmark != 0)
> - skp = smack_from_secid(skb->secmark);
> + skp = smack_from_secid(smk_of_secmark(skb-
> >secmark));
> else
> skp = smack_ipv6host_label(&sadd);
> if (skp == NULL)
> @@ -3962,7 +3970,7 @@ static int smack_socket_getpeersec_dgram(struct
> socket *sock,
> break;
> case PF_INET:
> #ifdef CONFIG_SECURITY_SMACK_NETFILTER
> - s = skb->secmark;
> + s = smk_of_secmark(skb->secmark);
> if (s != 0)
> break;
> #endif
> @@ -3981,7 +3989,7 @@ static int smack_socket_getpeersec_dgram(struct
> socket *sock,
> break;
> case PF_INET6:
> #ifdef SMACK_IPV6_SECMARK_LABELING
> - s = skb->secmark;
> + s = smk_of_secmark(skb->secmark);
> #endif
> break;
> }
> @@ -4060,7 +4068,7 @@ static int smack_inet_conn_request(struct sock
> *sk, struct sk_buff *skb,
> * The secmark is assumed to reflect policy better.
> */
> if (skb && skb->secmark != 0) {
> - skp = smack_from_secid(skb->secmark);
> + skp = smack_from_secid(smk_of_secmark(skb-
> >secmark));
> goto access_check;
> }
> #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
> @@ -4650,6 +4658,7 @@ static __init int smack_init(void)
> * Register with LSM
> */
> security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks),
> "smack");
> + smack_secids_index = smack_hooks[0].lsm_index;
> smack_enabled = 1;
>
> pr_info("Smack: Initializing.\n");
> diff --git a/security/smack/smack_netfilter.c
> b/security/smack/smack_netfilter.c
> index a5155295551f..510661ba6c16 100644
> --- a/security/smack/smack_netfilter.c
> +++ b/security/smack/smack_netfilter.c
> @@ -23,6 +23,19 @@
>
> #if IS_ENABLED(CONFIG_IPV6)
>
> +/*
> + * Reinvestigate this soon?
> + *
> + */
> +static u32 smack_to_secmark(u32 secid)
> +{
> + struct lsm_secids secids;
> +
> + lsm_secids_init(&secids);
> + secids.secid[smack_secids_index] = secid;
> + return lsm_secids_to_token(&secids);
> +}
> +
> static unsigned int smack_ipv6_output(void *priv,
> struct sk_buff *skb,
> const struct nf_hook_state
> *state)
> @@ -34,7 +47,7 @@ static unsigned int smack_ipv6_output(void *priv,
> if (sk && smack_sock(sk)) {
> ssp = smack_sock(sk);
> skp = ssp->smk_out;
> - skb->secmark = skp->smk_secid;
> + skb->secmark = smack_to_secmark(skp->smk_secid);
> }
>
> return NF_ACCEPT;
> @@ -52,7 +65,7 @@ static unsigned int smack_ipv4_output(void *priv,
> if (sk && smack_sock(sk)) {
> ssp = smack_sock(sk);
> skp = ssp->smk_out;
> - skb->secmark = skp->smk_secid;
> + skb->secmark = smack_to_secmark(skp->smk_secid);
> }
>
> return NF_ACCEPT;
> diff --git a/security/stacking.c b/security/stacking.c
> new file mode 100644
> index 000000000000..65276cd695de
> --- /dev/null
> +++ b/security/stacking.c
> @@ -0,0 +1,165 @@
> +/*
> + * Maintain a mapping between the secid used in networking
> + * and the set of secids used by the security modules.
> + *
> + * Author:
> + * Casey Schaufler <casey at schaufler-ca.com>
> + *
> + * Copyright (C) 2017 Casey Schaufler <casey at schaufler-ca.com>
> + * Copyright (C) 2017 Intel Corporation.
> + *
> + * This program is free software; you can redistribute it
> and/or modify
> + * it under the terms of the GNU General Public License
> version 2,
> + * as published by the Free Software Foundation.
> + */
> +
> +#include <linux/lsm_hooks.h>
> +
> +struct token_entry {
> + int used; /* relative age of
> the entry */
> + u32 token; /* token value */
> + struct lsm_secids secids; /* secids mapped to
> this token */
> +};
> +
> +/*
> + * Add an entry to the table when asked for a mapping that
> + * isn't already present. If the table is full throw away the
> + * least recently used entry. If the entry is present undate
> + * when it was used.
> + */
> +#define TOKEN_AGE_LIMIT (MAX_INT >> 2)
> +#define TOKEN_LIMIT 0x20000000
> +#define TOKEN_SET_SIZE 200
> +#define TOKEN_BIT 0x80000000
> +int token_used;
> +u32 token_next;
> +struct lsm_secids null_secids;
> +struct token_entry token_set[TOKEN_SET_SIZE];
> +
> +#ifdef CONFIG_SECURITY_LSM_DEBUG
> +static void report_token(const char *msg, const struct token_entry
> *te)
> +{
> + int i;
> +
> + pr_info("LSM: %s token=%08x %u,%u,%u,%u,%u,%u,%u,%u\n", msg,
> te->token,
> + te->secids.secid[0], te->secids.secid[1], te-
> >secids.secid[2],
> + te->secids.secid[3], te->secids.secid[4], te-
> >secids.secid[5],
> + te->secids.secid[6], te->secids.secid[7]);
> + for (i = 0; i < LSM_MAX_MAJOR; i++)
> + if (te->secids.secid[i] & TOKEN_BIT)
> + pr_info("LSM: module %d provided a
> token.\n", i);
> +}
> +#else
> +static inline void report_token(const char *msg, const struct
> token_entry *te)
> +{
> +}
> +#endif
> +
> +static int next_used(void)
> +{
> + if (token_next >= TOKEN_LIMIT) {
> + pr_info("LSM: Security token use overflow - safe
> reset\n");
> + token_used = 0;
> + }
> + return ++token_used;
> +}
> +
> +static u32 next_token(void)
> +{
> + if (token_next >= TOKEN_LIMIT) {
> + pr_info("LSM: Security token overflow - safe
> reset\n");
> + token_next = 0;
> + }
> + return ++token_next | TOKEN_BIT;
> +}
> +
> +u32 lsm_secids_to_token(const struct lsm_secids *secids)
> +{
> + int i;
> + int j;
> + int old;
> +
> +#ifdef CONFIG_SECURITY_LSM_DEBUG
> + for (i = 0; i < LSM_MAX_MAJOR; i++)
> + if (secids->secid[i] & TOKEN_BIT)
> + pr_info("LSM: %s secid[%d]=%08x has token
> bit\n",
> + __func__, i, secids->secid[i]);
> +#endif
> +
> + /*
> + * If none of the secids are set whoever sent this here
> + * was thinking "0".
> + */
> + if (!memcmp(secids, &null_secids, sizeof(*secids)))
> + return 0;
> +
> + for (i = 0; i < TOKEN_SET_SIZE; i++) {
> + if (token_set[i].token == 0)
> + break;
> + if (!memcmp(secids, &token_set[i].secids,
> sizeof(*secids))) {
> + token_set[i].used = next_used();
> + return token_set[i].token;
> + }
> + }
> + if (i == TOKEN_SET_SIZE) {
> + old = token_used;
> + for (j = 0; j < TOKEN_SET_SIZE; j++) {
> + if (token_set[j].used < old) {
> + old = token_set[j].used;
> + i = j;
> + }
> + }
> + }
> + token_set[i].secids = *secids;
> + token_set[i].token = next_token();
> + token_set[i].used = next_used();
> +
> + report_token("new", &token_set[i]);
> +
> + return token_set[i].token;
> +}
> +
> +void lsm_token_to_secids(const u32 token, struct lsm_secids *secids)
> +{
> + int i;
> + struct lsm_secids fudge;
> +
> + if (token) {
> + if (!(token & TOKEN_BIT)) {
> +#ifdef CONFIG_SECURITY_LSM_DEBUG
> + pr_info("LSM: %s token=%08x has no token
> bit\n",
> + __func__, token);
> +#endif
> + for (i = 0; i < LSM_MAX_MAJOR; i++)
> + fudge.secid[i] = token;
> + *secids = fudge;
> + return;
> + }
> + for (i = 0; i < TOKEN_SET_SIZE; i++) {
> + if (token_set[i].token == 0)
> + break;
> + if (token_set[i].token == token) {
> + *secids = token_set[i].secids;
> + token_set[i].used = next_used();
> + return;
> + }
> + }
> +#ifdef CONFIG_SECURITY_LSM_DEBUG
> + pr_info("LSM: %s token=%u was not found\n", __func__,
> token);
> +#endif
> + }
> + *secids = null_secids;
> +}
> +
> +u32 lsm_token_to_module_secid(const u32 token, int lsm)
> +{
> + struct lsm_secids secids;
> +
> + lsm_token_to_secids(token, &secids);
> + return secids.secid[lsm];
> +}
> +
> +void lsm_secids_init(struct lsm_secids *secids)
> +{
> + *secids = null_secids;
> +}
ENOLOCKING
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
More information about the Linux-security-module-archive
mailing list