lsm: split the xfrm_state_alloc_security() hook implementation

[~andy/linux] / security / selinux / xfrm.c

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index d030818862146732ebe30c8cc3f266d485ef0677..07ae0c06dfc34493688fd36f70c4dcb7285891f4 100644 (file)
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -73,6 +73,54 @@ static inline int selinux_authorizable_xfrm(struct xfrm_state *x)
        return selinux_authorizable_ctx(x->security);
 }
 
+/*
+ * Allocates a xfrm_sec_state and populates it using the supplied security
+ * xfrm_user_sec_ctx context.
+ */
+static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
+                                  struct xfrm_user_sec_ctx *uctx)
+{
+       int rc;
+       const struct task_security_struct *tsec = current_security();
+       struct xfrm_sec_ctx *ctx = NULL;
+       u32 str_len;
+
+       if (ctxp == NULL || uctx == NULL ||
+           uctx->ctx_doi != XFRM_SC_DOI_LSM ||
+           uctx->ctx_alg != XFRM_SC_ALG_SELINUX)
+               return -EINVAL;
+
+       str_len = uctx->ctx_len;
+       if (str_len >= PAGE_SIZE)
+               return -ENOMEM;
+
+       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;
+}
+
 /*
  * LSM hook implementation that authorizes that a flow can use
  * a xfrm policy rule.
@@ -190,96 +238,6 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
        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;
-}
-
 /*
  * LSM hook implementation that allocs and transfers uctx spec to
  * xfrm_policy.
@@ -287,15 +245,7 @@ out2:
 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);
 }
 
 
@@ -347,20 +297,51 @@ int selinux_xfrm_policy_delete(struct xfrm_sec_ctx *ctx)
 }
 
 /*
- * LSM hook implementation that allocs and transfers sec_ctx spec to
- * xfrm_state.
+ * 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 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;
 
-       BUG_ON(!x);
+       if (!polsec)
+               return 0;
 
-       err = selinux_xfrm_sec_ctx_alloc(&x->security, uctx, secid);
-       if (err == 0)
-               atomic_inc(&selinux_xfrm_refcount);
-       return err;
+       if (secid == 0)
+               return -EINVAL;
+
+       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;
 }
 
 /*