1 files changed, 202 insertions, 251 deletions

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index d03081886214..a91d205ec0c6 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -56,7 +56,7 @@
 atomic_t selinux_xfrm_refcount = ATOMIC_INIT(0);
 
 /*
- * Returns true if an LSM/SELinux context
+ * Returns true if the context is an LSM/SELinux context.
  */
 static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx)
 {
@@ -66,7 +66,7 @@ static inline int selinux_authorizable_ctx(struct xfrm_sec_ctx *ctx)
 }
 
 /*
- * Returns true if the xfrm contains a security blob for SELinux
+ * Returns true if the xfrm contains a security blob for SELinux.
  */
 static inline int selinux_authorizable_xfrm(struct xfrm_state *x)
 {
@@ -74,48 +74,111 @@ static inline int selinux_authorizable_xfrm(struct xfrm_state *x)
 }
 
 /*
- * LSM hook implementation that authorizes that a flow can use
- * a xfrm policy rule.
+ * Allocates a xfrm_sec_state and populates it using the supplied security
+ * xfrm_user_sec_ctx context.
  */
-int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir)
+static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
+                                   struct xfrm_user_sec_ctx *uctx)
 {
         int rc;
-        u32 sel_sid;
+        const struct task_security_struct *tsec = current_security();
+        struct xfrm_sec_ctx *ctx = NULL;
+        u32 str_len;
 
-        /* Context sid is either set to label or ANY_ASSOC */
-        if (ctx) {
-                if (!selinux_authorizable_ctx(ctx))
-                        return -EINVAL;
-
-                sel_sid = ctx->ctx_sid;
-        } else
-                /*
-                 * All flows should be treated as polmatch'ing an
-                 * otherwise applicable "non-labeled" policy. This
-                 * would prevent inadvertent "leaks".
-                 */
-                return 0;
+        if (ctxp == NULL || uctx == NULL ||
+            uctx->ctx_doi != XFRM_SC_DOI_LSM ||
+            uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
+                return -EINVAL;
 
-        rc = avc_has_perm(fl_secid, sel_sid, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__POLMATCH,
-                          NULL);
+        str_len = uctx->ctx_len;
+        if (str_len >= PAGE_SIZE)
+                return -ENOMEM;
 
-        if (rc == -EACCES)
-                return -ESRCH;
+        ctx = kmalloc(sizeof(*ctx) + str_len + 1, GFP_KERNEL);
+        if (!ctx)
+                return -ENOMEM;
 
+        ctx->ctx_doi = XFRM_SC_DOI_LSM;
+        ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
+        ctx->ctx_len = str_len;
+        memcpy(ctx->ctx_str, &uctx[1], str_len);
+        ctx->ctx_str[str_len] = '\0';
+        rc = security_context_to_sid(ctx->ctx_str, str_len, &ctx->ctx_sid);
+        if (rc)
+                goto err;
+
+        rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
+                          SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL);
+        if (rc)
+                goto err;
+
+        *ctxp = ctx;
+        atomic_inc(&selinux_xfrm_refcount);
+        return 0;
+
+err:
+        kfree(ctx);
         return rc;
 }
 
 /*
+ * Free the xfrm_sec_ctx structure.
+ */
+static void selinux_xfrm_free(struct xfrm_sec_ctx *ctx)
+{
+        if (!ctx)
+                return;
+
+        atomic_dec(&selinux_xfrm_refcount);
+        kfree(ctx);
+}
+
+/*
+ * Authorize the deletion of a labeled SA or policy rule.
+ */
+static int selinux_xfrm_delete(struct xfrm_sec_ctx *ctx)
+{
+        const struct task_security_struct *tsec = current_security();
+
+        if (!ctx)
+                return 0;
+
+        return avc_has_perm(tsec->sid, ctx->ctx_sid,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
+                            NULL);
+}
+
+/*
+ * LSM hook implementation that authorizes that a flow can use a xfrm policy
+ * rule.
+ */
+int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir)
+{
+        int rc;
+
+        /* All flows should be treated as polmatch'ing an otherwise applicable
+         * "non-labeled" policy. This would prevent inadvertent "leaks". */
+        if (!ctx)
+                return 0;
+
+        /* Context sid is either set to label or ANY_ASSOC */
+        if (!selinux_authorizable_ctx(ctx))
+                return -EINVAL;
+
+        rc = avc_has_perm(fl_secid, ctx->ctx_sid,
+                          SECCLASS_ASSOCIATION, ASSOCIATION__POLMATCH, NULL);
+        return (rc == -EACCES ? -ESRCH : rc);
+}
+
+/*
  * LSM hook implementation that authorizes that a state matches
  * the given policy, flow combo.
  */
-
-int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp,
-                        const struct flowi *fl)
+int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x,
+                                      struct xfrm_policy *xp,
+                                      const struct flowi *fl)
 {
         u32 state_sid;
-        int rc;
 
         if (!xp->security)
                 if (x->security)
@@ -138,187 +201,80 @@ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *
         if (fl->flowi_secid != state_sid)
                 return 0;
 
-        rc = avc_has_perm(fl->flowi_secid, state_sid, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__SENDTO,
-                          NULL)? 0:1;
-
-        /*
-         * 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 rc;
+        /* 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,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO,
+                            NULL) ? 0 : 1);
 }
 
 /*
  * LSM hook implementation that checks and/or returns the xfrm sid for the
  * incoming packet.
  */
-
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
 {
+        u32 sid_session = SECSID_NULL;
         struct sec_path *sp;
 
-        *sid = SECSID_NULL;
-
         if (skb == NULL)
-                return 0;
+                goto out;
 
         sp = skb->sp;
         if (sp) {
-                int i, sid_set = 0;
+                int i;
 
-                for (i = sp->len-1; i >= 0; i--) {
+                for (i = sp->len - 1; i >= 0; i--) {
                         struct xfrm_state *x = sp->xvec[i];
                         if (selinux_authorizable_xfrm(x)) {
                                 struct xfrm_sec_ctx *ctx = x->security;
 
-                                if (!sid_set) {
-                                        *sid = ctx->ctx_sid;
-                                        sid_set = 1;
-
+                                if (sid_session == SECSID_NULL) {
+                                        sid_session = ctx->ctx_sid;
                                         if (!ckall)
-                                                break;
-                                } else if (*sid != ctx->ctx_sid)
+                                                goto out;
+                                } else if (sid_session != ctx->ctx_sid) {
+                                        *sid = SECSID_NULL;
                                         return -EINVAL;
+                                }
                         }
                 }
         }
 
-        return 0;
-}
-
-/*
- * Security blob allocation for xfrm_policy and xfrm_state
- * CTX does not have a meaningful value on input
- */
-static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp,
-        struct xfrm_user_sec_ctx *uctx, u32 sid)
-{
-        int rc = 0;
-        const struct task_security_struct *tsec = current_security();
-        struct xfrm_sec_ctx *ctx = NULL;
-        char *ctx_str = NULL;
-        u32 str_len;
-
-        BUG_ON(uctx && sid);
-
-        if (!uctx)
-                goto not_from_user;
-
-        if (uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
-                return -EINVAL;
-
-        str_len = uctx->ctx_len;
-        if (str_len >= PAGE_SIZE)
-                return -ENOMEM;
-
-        *ctxp = ctx = kmalloc(sizeof(*ctx) +
-                              str_len + 1,
-                              GFP_KERNEL);
-
-        if (!ctx)
-                return -ENOMEM;
-
-        ctx->ctx_doi = uctx->ctx_doi;
-        ctx->ctx_len = str_len;
-        ctx->ctx_alg = uctx->ctx_alg;
-
-        memcpy(ctx->ctx_str,
-               uctx+1,
-               str_len);
-        ctx->ctx_str[str_len] = 0;
-        rc = security_context_to_sid(ctx->ctx_str,
-                                     str_len,
-                                     &ctx->ctx_sid);
-
-        if (rc)
-                goto out;
-
-        /*
-         * Does the subject have permission to set security context?
-         */
-        rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
-                          SECCLASS_ASSOCIATION,
-                          ASSOCIATION__SETCONTEXT, NULL);
-        if (rc)
-                goto out;
-
-        return rc;
-
-not_from_user:
-        rc = security_sid_to_context(sid, &ctx_str, &str_len);
-        if (rc)
-                goto out;
-
-        *ctxp = ctx = kmalloc(sizeof(*ctx) +
-                              str_len,
-                              GFP_ATOMIC);
-
-        if (!ctx) {
-                rc = -ENOMEM;
-                goto out;
-        }
-
-        ctx->ctx_doi = XFRM_SC_DOI_LSM;
-        ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
-        ctx->ctx_sid = sid;
-        ctx->ctx_len = str_len;
-        memcpy(ctx->ctx_str,
-               ctx_str,
-               str_len);
-
-        goto out2;
-
 out:
-        *ctxp = NULL;
-        kfree(ctx);
-out2:
-        kfree(ctx_str);
-        return rc;
+        *sid = sid_session;
+        return 0;
 }
 
 /*
- * LSM hook implementation that allocs and transfers uctx spec to
- * xfrm_policy.
+ * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy.
  */
 int selinux_xfrm_policy_alloc(struct xfrm_sec_ctx **ctxp,
                               struct xfrm_user_sec_ctx *uctx)
 {
-        int err;
-
-        BUG_ON(!uctx);
-
-        err = selinux_xfrm_sec_ctx_alloc(ctxp, uctx, 0);
-        if (err == 0)
-                atomic_inc(&selinux_xfrm_refcount);
-
-        return err;
+        return selinux_xfrm_alloc_user(ctxp, uctx);
 }
 
-
 /*
- * LSM hook implementation that copies security data structure from old to
- * new for policy cloning.
+ * LSM hook implementation that copies security data structure from old to new
+ * for policy cloning.
  */
 int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx,
                               struct xfrm_sec_ctx **new_ctxp)
 {
         struct xfrm_sec_ctx *new_ctx;
 
-        if (old_ctx) {
-                new_ctx = kmalloc(sizeof(*old_ctx) + old_ctx->ctx_len,
-                                  GFP_ATOMIC);
-                if (!new_ctx)
-                        return -ENOMEM;
+        if (!old_ctx)
+                return 0;
+
+        new_ctx = kmemdup(old_ctx, sizeof(*old_ctx) + old_ctx->ctx_len,
+                          GFP_ATOMIC);
+        if (!new_ctx)
+                return -ENOMEM;
+        atomic_inc(&selinux_xfrm_refcount);
+        *new_ctxp = new_ctx;
 
-                memcpy(new_ctx, old_ctx, sizeof(*new_ctx));
-                memcpy(new_ctx->ctx_str, old_ctx->ctx_str, new_ctx->ctx_len);
-                atomic_inc(&selinux_xfrm_refcount);
-                *new_ctxp = new_ctx;
-        }
         return 0;
 }
 
@@ -327,8 +283,7 @@ int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_ctx,
  */
 void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx)
 {
-        atomic_dec(&selinux_xfrm_refcount);
-        kfree(ctx);
+        selinux_xfrm_free(ctx);
 }
 
 /*
@@ -336,31 +291,55 @@ void selinux_xfrm_policy_free(struct xfrm_sec_ctx *ctx)
  */
 int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx)
 {
-        const struct task_security_struct *tsec = current_security();
-
-        if (!ctx)
-                return 0;
+        return selinux_xfrm_delete(ctx);
+}
 
-        return avc_has_perm(tsec->sid, ctx->ctx_sid,
-                            SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
-                            NULL);
+/*
+ * LSM hook implementation that allocates a xfrm_sec_state, populates it using
+ * the supplied security context, and assigns it to the xfrm_state.
+ */
+int selinux_xfrm_state_alloc(struct xfrm_state *x,
+                             struct xfrm_user_sec_ctx *uctx)
+{
+        return selinux_xfrm_alloc_user(&x->security, uctx);
 }
 
 /*
- * LSM hook implementation that allocs and transfers sec_ctx spec to
- * xfrm_state.
+ * LSM hook implementation that allocates a xfrm_sec_state and populates based
+ * on a secid.
  */
-int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uctx,
-                u32 secid)
+int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x,
+                                     struct xfrm_sec_ctx *polsec, u32 secid)
 {
-        int err;
+        int rc;
+        struct xfrm_sec_ctx *ctx;
+        char *ctx_str = NULL;
+        int str_len;
+
+        if (!polsec)
+                return 0;
 
-        BUG_ON(!x);
+        if (secid == 0)
+                return -EINVAL;
 
-        err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx, secid);
-        if (err == 0)
-                atomic_inc(&selinux_xfrm_refcount);
-        return err;
+        rc = security_sid_to_context(secid, &ctx_str, &str_len);
+        if (rc)
+                return rc;
+
+        ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC);
+        if (!ctx)
+                return -ENOMEM;
+
+        ctx->ctx_doi = XFRM_SC_DOI_LSM;
+        ctx->ctx_alg = XFRM_SC_ALG_SELINUX;
+        ctx->ctx_sid = secid;
+        ctx->ctx_len = str_len;
+        memcpy(ctx->ctx_str, ctx_str, str_len);
+        kfree(ctx_str);
+
+        x->security = ctx;
+        atomic_inc(&selinux_xfrm_refcount);
+        return 0;
 }
 
 /*
@@ -368,24 +347,15 @@ int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uct
  */
 void selinux_xfrm_state_free(struct xfrm_state *x)
 {
-        atomic_dec(&selinux_xfrm_refcount);
-        kfree(x->security);
+        selinux_xfrm_free(x->security);
 }
 
- /*
-  * LSM hook implementation that authorizes deletion of labeled SAs.
-  */
+/*
+ * LSM hook implementation that authorizes deletion of labeled SAs.
+ */
 int selinux_xfrm_state_delete(struct xfrm_state *x)
 {
-        const struct task_security_struct *tsec = current_security();
-        struct xfrm_sec_ctx *ctx = x->security;
-
-        if (!ctx)
-                return 0;
-
-        return avc_has_perm(tsec->sid, ctx->ctx_sid,
-                            SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
-                            NULL);
+        return selinux_xfrm_delete(x->security);
 }
 
 /*
@@ -395,14 +365,12 @@ int selinux_xfrm_state_delete(struct xfrm_state *x)
  * we need to check for unlabelled access since this may not have
  * gone thru the IPSec process.
  */
-int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
-                                struct common_audit_data *ad)
+int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb,
+                              struct common_audit_data *ad)
 {
-        int i, rc = 0;
-        struct sec_path *sp;
-        u32 sel_sid = SECINITSID_UNLABELED;
-
-        sp = skb->sp;
+        int i;
+        struct sec_path *sp = skb->sp;
+        u32 peer_sid = SECINITSID_UNLABELED;
 
         if (sp) {
                 for (i = 0; i < sp->len; i++) {
@@ -410,23 +378,17 @@ int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
 
                         if (x && selinux_authorizable_xfrm(x)) {
                                 struct xfrm_sec_ctx *ctx = x->security;
-                                sel_sid = ctx->ctx_sid;
+                                peer_sid = ctx->ctx_sid;
                                 break;
                         }
                 }
         }
 
-        /*
-         * This check even when there's no association involved is
-         * intended, according to Trent Jaeger, to make sure a
-         * process can't engage in non-ipsec communication unless
-         * explicitly allowed by policy.
-         */
-
-        rc = avc_has_perm(isec_sid, sel_sid, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__RECVFROM, ad);
-
-        return rc;
+        /* This check even when there's no association involved is intended,
+         * according to Trent Jaeger, to make sure a process can't engage in
+         * non-IPsec communication unless explicitly allowed by policy. */
+        return avc_has_perm(sk_sid, peer_sid,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__RECVFROM, ad);
 }
 
 /*
@@ -436,49 +398,38 @@ int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
  * If we do have a authorizable security association, then it has already been
  * checked in the selinux_xfrm_state_pol_flow_match hook above.
  */
-int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-                                        struct common_audit_data *ad, u8 proto)
+int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb,
+                                struct common_audit_data *ad, u8 proto)
 {
         struct dst_entry *dst;
-        int rc = 0;
-
-        dst = skb_dst(skb);
-
-        if (dst) {
-                struct dst_entry *dst_test;
-
-                for (dst_test = dst; dst_test != NULL;
-                     dst_test = dst_test->child) {
-                        struct xfrm_state *x = dst_test->xfrm;
-
-                        if (x && selinux_authorizable_xfrm(x))
-                                goto out;
-                }
-        }
 
         switch (proto) {
         case IPPROTO_AH:
         case IPPROTO_ESP:
         case IPPROTO_COMP:
-                /*
-                 * We should have already seen this packet once before
-                 * it underwent xfrm(s). No need to subject it to the
-                 * unlabeled check.
-                 */
-                goto out;
+                /* We should have already seen this packet once before it
+                 * underwent xfrm(s). No need to subject it to the unlabeled
+                 * check. */
+                return 0;
         default:
                 break;
         }
 
-        /*
-         * This check even when there's no association involved is
-         * intended, according to Trent Jaeger, to make sure a
-         * process can't engage in non-ipsec communication unless
-         * explicitly allowed by policy.
-         */
+        dst = skb_dst(skb);
+        if (dst) {
+                struct dst_entry *iter;
 
-        rc = avc_has_perm(isec_sid, SECINITSID_UNLABELED, SECCLASS_ASSOCIATION,
-                          ASSOCIATION__SENDTO, ad);
-out:
-        return rc;
+                for (iter = dst; iter != NULL; iter = iter->child) {
+                        struct xfrm_state *x = iter->xfrm;
+
+                        if (x && selinux_authorizable_xfrm(x))
+                                return 0;
+                }
+        }
+
+        /* This check even when there's no association involved is intended,
+         * according to Trent Jaeger, to make sure a process can't engage in
+         * non-IPsec communication unless explicitly allowed by policy. */
+        return avc_has_perm(sk_sid, SECINITSID_UNLABELED,
+                            SECCLASS_ASSOCIATION, ASSOCIATION__SENDTO, ad);
 }