From c1afbd39e1769d705dcbf08482f91c1e6c939e8f Mon Sep 17 00:00:00 2001 From: shyouhei Date: Fri, 18 Feb 2011 10:42:50 +0000 Subject: [PATCH] * lib/fileutils.rb (FileUtils::remove_entry_secure): there is a race condition in the case where the given path is a directory, and some other user can move that directory, and create a symlink while this method is executing. Reported by: Nicholas Jefferson git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@30896 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 8 ++++++++ lib/fileutils.rb | 13 +++++++++---- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/ChangeLog b/ChangeLog index e07088c476..0139fabaf2 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +Fri Feb 18 19:31:31 2011 Shugo Maeda + + * lib/fileutils.rb (FileUtils::remove_entry_secure): there is a + race condition in the case where the given path is a directory, + and some other user can move that directory, and create a + symlink while this method is executing. + Reported by: Nicholas Jefferson + Fri Feb 18 00:28:39 2011 CHIKANAGA Tomoyuki * compile.c (get_exception_sym2type): guard temporary object from GC. diff --git a/lib/fileutils.rb b/lib/fileutils.rb index 1023ae3063..9cd1a7cc76 100644 --- a/lib/fileutils.rb +++ b/lib/fileutils.rb @@ -667,10 +667,10 @@ module FileUtils # removing directories. This requires the current process is the # owner of the removing whole directory tree, or is the super user (root). # - # WARNING: You must ensure that *ALL* parent directories are not - # world writable. Otherwise this method does not work. - # Only exception is temporary directory like /tmp and /var/tmp, - # whose permission is 1777. + # WARNING: You must ensure that *ALL* parent directories cannot be + # moved by other untrusted users. For example, parent directories + # should not be owned by untrusted users, and should not be world + # writable except when the sticky bit set. # # WARNING: Only the owner of the removing directory tree, or Unix super # user (root) should invoke this method. Otherwise this method does not @@ -713,6 +713,11 @@ module FileUtils end f.chown euid, -1 f.chmod 0700 + unless fu_stat_identical_entry?(st, File.lstat(fullpath)) + # TOC-to-TOU attack? + File.unlink fullpath + return + end } # ---- tree root is frozen ---- root = Entry_.new(path)