tests/chown/preserve-root.sh

   1 #!/bin/sh
   2 # Verify that --preserve-root works.
   3
   4 # Copyright (C) 2006-2024 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ chown
  21 skip_if_root_
  22
  23 id_g=$(id -g) && test -n "$id_g" || framework_failure_
  24 case $(id -gn) in
  25   nogroup) id_g= ;; # In macOS, users can be in nogroup but cannot chgrp to it.
  26 esac
  27
  28 mkdir d && ln -s / d/slink-to-root
  29
  30
  31 # Even if --preserve-root were to malfunction, allowing the chown or
  32 # chgrp to traverse through "/", since we're running as non-root,
  33 # they would be very unlikely to cause any changes.
  34 chown -R --preserve-root 0 / >  out 2>&1 && fail=1
  35 chgrp -R --preserve-root 0 / >> out 2>&1 && fail=1
  36
  37 # Here, if --preserve-root were to malfunction, chmod could make changes,
  38 # but only to files owned and unreadable by the user running this test,
  39 # and then, only to make them readable by owner.
  40 chmod -R --preserve-root u+r / >> out 2>&1 && fail=1
  41
  42 # With -RHh, --preserve-root should trigger nothing,
  43 # since the symlink in question is not a command line argument.
  44 # Contrary to the above commands, these two should succeed.
  45 echo '==== test -RHh' >> out || framework_failure_
  46 chown -RHh --preserve-root $(id -u) d >> out 2>&1 || fail=1
  47 test -z "$id_g" || chgrp -RHh --preserve-root "$id_g" d >> out 2>&1 || fail=1
  48
  49 # These must fail.
  50 echo '==== test -RLh' >> out || framework_failure_
  51 chown -RLh --preserve-root $(id -u) d >> out 2>&1 && fail=1
  52 test -n "$id_g" && chgrp -RLh --preserve-root "$id_g" d >> out 2>&1 && fail=1
  53
  54 (
  55  cat <<\EOF &&
  56 chown: it is dangerous to operate recursively on '/'
  57 chown: use --no-preserve-root to override this failsafe
  58 chgrp: it is dangerous to operate recursively on '/'
  59 chgrp: use --no-preserve-root to override this failsafe
  60 chmod: it is dangerous to operate recursively on '/'
  61 chmod: use --no-preserve-root to override this failsafe
  62 ==== test -RHh
  63 ==== test -RLh
  64 chown: it is dangerous to operate recursively on 'd/slink-to-root' (same as '/')
  65 chown: use --no-preserve-root to override this failsafe
  66 EOF
  67  { test -z "$id_g" || cat <<\EOF; }
  68 chgrp: it is dangerous to operate recursively on 'd/slink-to-root' (same as '/')
  69 chgrp: use --no-preserve-root to override this failsafe
  70 EOF
  71 ) > exp || framework_failure_
  72
  73 compare exp out || fail=1
  74
  75 Exit $fail