From 1cf427ee6380045c8f93216b80f63890926508af Mon Sep 17 00:00:00 2001
From: Go MAEDA <maeda@farend.jp>
Date: Fri, 23 Apr 2021 00:46:45 +0000
Subject: [PATCH] Stricter validation of given revisions of repositories
 (#35085).

Patch by Holger Just.


git-svn-id: http://svn.redmine.org/redmine/trunk@20962 e93f8b46-1217-0410-a6f0-8f06a7374b81
---
 app/controllers/repositories_controller.rb    | 21 ++++++++++++-------
 app/models/repository.rb                      |  4 ++++
 lib/redmine/scm/adapters/abstract_adapter.rb  |  8 +++++++
 lib/redmine/scm/adapters/git_adapter.rb       | 12 +++++++++++
 lib/redmine/scm/adapters/mercurial_adapter.rb |  9 ++++++++
 5 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/app/controllers/repositories_controller.rb b/app/controllers/repositories_controller.rb
index dfa96cc0e..45e969ba4 100644
--- a/app/controllers/repositories_controller.rb
+++ b/app/controllers/repositories_controller.rb
@@ -330,7 +330,7 @@ class RepositoriesController < ApplicationController
     render_404
   end
 
-  REV_PARAM_RE = %r{\A[a-f0-9]*\Z}i
+  REV_PARAM_RE = %r{\A[a-f0-9]*\z}i
 
   def find_project_repository
     @project = Project.find(params[:id])
@@ -341,14 +341,12 @@ class RepositoriesController < ApplicationController
     end
     (render_404; return false) unless @repository
     @path = params[:path].is_a?(Array) ? params[:path].join('/') : params[:path].to_s
-    @rev = params[:rev].blank? ? @repository.default_branch : params[:rev].to_s.strip
-    @rev_to = params[:rev_to]
 
-    unless REV_PARAM_RE.match?(@rev.to_s) && REV_PARAM_RE.match?(@rev_to.to_s)
-      if @repository.branches.blank?
-        raise InvalidRevisionParam
-      end
-    end
+    @rev = params[:rev].to_s.strip.presence || @repository.default_branch
+    raise InvalidRevisionParam unless valid_name?(@rev)
+
+    @rev_to = params[:rev_to].to_s.strip.presence
+    raise InvalidRevisionParam unless valid_name?(@rev_to)
   rescue ActiveRecord::RecordNotFound
     render_404
   rescue InvalidRevisionParam
@@ -433,4 +431,11 @@ class RepositoriesController < ApplicationController
       'attachment'
     end
   end
+
+  def valid_name?(rev)
+    return true if rev.nil?
+    return true if REV_PARAM_RE.match?(rev)
+
+    @repository ? @repository.valid_name?(rev) : true
+  end
 end
diff --git a/app/models/repository.rb b/app/models/repository.rb
index e65c800e6..4e76c3453 100644
--- a/app/models/repository.rb
+++ b/app/models/repository.rb
@@ -463,6 +463,10 @@ class Repository < ActiveRecord::Base
     scope
   end
 
+  def valid_name?(name)
+    scm.valid_name?(name)
+  end
+
   protected
 
   # Validates repository url based against an optional regular expression
diff --git a/lib/redmine/scm/adapters/abstract_adapter.rb b/lib/redmine/scm/adapters/abstract_adapter.rb
index dae621866..d0c3293a6 100644
--- a/lib/redmine/scm/adapters/abstract_adapter.rb
+++ b/lib/redmine/scm/adapters/abstract_adapter.rb
@@ -176,6 +176,14 @@ module Redmine
           (path[-1, 1] == "/") ? path[0..-2] : path
         end
 
+        def valid_name?(name)
+          return true if name.nil?
+          return true if name.is_a?(Integer) && name > 0
+          return true if name.is_a?(String) && name =~ /\A[0-9]*\z/
+
+          false
+        end
+
         private
 
         def retrieve_root_url
diff --git a/lib/redmine/scm/adapters/git_adapter.rb b/lib/redmine/scm/adapters/git_adapter.rb
index b85bd0296..363476cd4 100644
--- a/lib/redmine/scm/adapters/git_adapter.rb
+++ b/lib/redmine/scm/adapters/git_adapter.rb
@@ -420,6 +420,18 @@ module Redmine
           nil
         end
 
+        def valid_name?(name)
+          return false unless name.is_a?(String)
+
+          return false if name.start_with?('-', '/', 'refs/heads/', 'refs/remotes/')
+          return false if name == 'HEAD'
+
+          git_cmd ['show-ref', '--heads', '--tags', '--quiet', '--', name]
+          true
+        rescue ScmCommandAborted
+          false
+        end
+
         class Revision < Redmine::Scm::Adapters::Revision
           # Returns the readable identifier
           def format_identifier
diff --git a/lib/redmine/scm/adapters/mercurial_adapter.rb b/lib/redmine/scm/adapters/mercurial_adapter.rb
index 6ab5ec69d..075636ce1 100644
--- a/lib/redmine/scm/adapters/mercurial_adapter.rb
+++ b/lib/redmine/scm/adapters/mercurial_adapter.rb
@@ -296,6 +296,15 @@ module Redmine
           Annotate.new
         end
 
+        def valid_name?(name)
+          return false unless name.nil? || name.is_a?(String)
+
+          # Mercurials names don't need to be checked further as its CLI
+          # interface is restrictive enough to reject any invalid names on its
+          # own.
+          true
+        end
+
         class Revision < Redmine::Scm::Adapters::Revision
           # Returns the readable identifier
           def format_identifier
-- 
2.39.5