selinux: fix the labeled xfrm/IPsec reference count handling

The SELinux labeled IPsec code was improperly handling its reference
counting, dropping a reference on a delete operation instead of on a
free/release operation.

Reported-by: Ondrej Moris <omoris@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 8ab2951..d030818 100644 (file)
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -316,6 +316,7 @@ int selinux_xfrm_policy_clone(struct xfrm_sec_ctx *old_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;
@@ -326,6 +327,7 @@ 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);
 }
 
@@ -335,17 +337,13 @@ 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();
-       int rc = 0;
 
-       if (ctx) {
-               rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
-                                 SECCLASS_ASSOCIATION,
-                                 ASSOCIATION__SETCONTEXT, NULL);
-               if (rc == 0)
-                       atomic_dec(&selinux_xfrm_refcount);
-       }
+       if (!ctx)
+               return 0;
 
-       return rc;
+       return avc_has_perm(tsec->sid, ctx->ctx_sid,
+                           SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
+                           NULL);
 }
 
 /*
@@ -370,8 +368,8 @@ int selinux_xfrm_state_alloc(struct xfrm_state *x, struct xfrm_user_sec_ctx *uct
  */
 void selinux_xfrm_state_free(struct xfrm_state *x)
 {
-       struct xfrm_sec_ctx *ctx = x->security;
-       kfree(ctx);
+       atomic_dec(&selinux_xfrm_refcount);
+       kfree(x->security);
 }
 
  /*
@@ -381,17 +379,13 @@ int selinux_xfrm_state_delete(struct xfrm_state *x)
 {
        const struct task_security_struct *tsec = current_security();
        struct xfrm_sec_ctx *ctx = x->security;
-       int rc = 0;
 
-       if (ctx) {
-               rc = avc_has_perm(tsec->sid, ctx->ctx_sid,
-                                 SECCLASS_ASSOCIATION,
-                                 ASSOCIATION__SETCONTEXT, NULL);
-               if (rc == 0)
-                       atomic_dec(&selinux_xfrm_refcount);
-       }
+       if (!ctx)
+               return 0;
 
-       return rc;
+       return avc_has_perm(tsec->sid, ctx->ctx_sid,
+                           SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT,
+                           NULL);
 }
 
 /*