view src/testdir/test_help.vim @ 33811:06219b3bdaf3 v9.0.2121

patch 9.0.2121: [security]: use-after-free in ex_substitute Commit: https://github.com/vim/vim/commit/26c11c56888d01e298cd8044caf860f3c26f57bb Author: Christian Brabandt <cb@256bit.org> Date: Wed Nov 22 21:26:41 2023 +0100 patch 9.0.2121: [security]: use-after-free in ex_substitute Problem: [security]: use-after-free in ex_substitute Solution: always allocate memory closes: #13552 A recursive :substitute command could cause a heap-use-after free in Vim (CVE-2023-48706). The whole reproducible test is a bit tricky, I can only reproduce this reliably when no previous substitution command has been used yet (which is the reason, the test needs to run as first one in the test_substitute.vim file) and as a combination of the `:~` command together with a :s command that contains the special substitution atom `~\=` which will make use of a sub-replace special atom and calls a vim script function. There was a comment in the existing :s code, that already makes the `sub` variable allocate memory so that a recursive :s call won't be able to cause any issues here, so this was known as a potential problem already. But for the current test-case that one does not work, because the substitution does not start with `\=` but with `~\=` (and since there does not yet exist a previous substitution atom, Vim will simply increment the `sub` pointer (which then was not allocated dynamically) and later one happily use a sub-replace special expression (which could then free the `sub` var). The following commit fixes this, by making the sub var always using allocated memory, which also means we need to free the pointer whenever we leave the function. Since sub is now always an allocated variable, we also do no longer need the sub_copy variable anymore, since this one was used to indicated when sub pointed to allocated memory (and had therefore to be freed on exit) and when not. Github Security Advisory: https://github.com/vim/vim/security/advisories/GHSA-c8qm-x72m-q53q Signed-off-by: Christian Brabandt <cb@256bit.org>
author Christian Brabandt <cb@256bit.org>
date Wed, 22 Nov 2023 22:15:05 +0100
parents bcd204e28fed
children
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" Tests for :help

source check.vim
import './vim9.vim' as v9

func Test_help_restore_snapshot()
  help
  set buftype=
  help
  edit x
  help
  helpclose
endfunc

func Test_help_restore_snapshot_split()
  " Squeeze the unnamed buffer, Xfoo and the help one side-by-side and focus
  " the first one before calling :help.
  let bnr = bufnr()
  botright vsp Xfoo
  wincmd h
  help
  wincmd L
  let g:did_bufenter = v:false
  augroup T
    au!
    au BufEnter Xfoo let g:did_bufenter = v:true
  augroup END
  helpclose
  augroup! T
  " We're back to the unnamed buffer.
  call assert_equal(bnr, bufnr())
  " No BufEnter was triggered for Xfoo.
  call assert_equal(v:false, g:did_bufenter)

  close!
  bwipe!
endfunc

func Test_help_errors()
  call assert_fails('help doesnotexist', 'E149:')
  call assert_fails('help!', 'E478:')
  if has('multi_lang')
    call assert_fails('help help@xy', 'E661:')
  endif

  let save_hf = &helpfile
  set helpfile=help_missing
  help
  call assert_equal(1, winnr('$'))
  call assert_notequal('help', &buftype)
  let &helpfile = save_hf

  call assert_fails('help ' . repeat('a', 1048), 'E149:')

  new
  set keywordprg=:help
  call setline(1, "   ")
  call assert_fails('normal VK', 'E349:')
  bwipe!
endfunc

func Test_help_expr()
  help expr-!~?
  call assert_equal('eval.txt', expand('%:t'))
  close
endfunc

func Test_help_keyword()
  new
  set keywordprg=:help
  call setline(1, "  Visual ")
  normal VK
  call assert_match('^Visual mode', getline('.'))
  call assert_equal('help', &ft)
  close
  bwipe!
endfunc

func Test_help_local_additions()
  call mkdir('Xruntime/doc', 'pR')
  call writefile(['*mydoc.txt* my awesome doc'], 'Xruntime/doc/mydoc.txt')
  call writefile(['*mydoc-ext.txt* my extended awesome doc'], 'Xruntime/doc/mydoc-ext.txt')
  let rtp_save = &rtp
  set rtp+=./Xruntime
  help local-additions
  let lines = getline(line(".") + 1, search("^$") - 1)
  call assert_equal([
  \ '|mydoc-ext.txt| my extended awesome doc',
  \ '|mydoc.txt| my awesome doc'
  \ ], lines)
  call delete('Xruntime/doc/mydoc-ext.txt')
  close

  call mkdir('Xruntime-ja/doc', 'pR')
  call writefile(["local-additions\thelp.jax\t/*local-additions*"], 'Xruntime-ja/doc/tags-ja')
  call writefile(['*help.txt* This is jax file', '',
  \ 'LOCAL ADDITIONS: *local-additions*', ''], 'Xruntime-ja/doc/help.jax')
  call writefile(['*work.txt* This is jax file'], 'Xruntime-ja/doc/work.jax')
  call writefile(['*work2.txt* This is jax file'], 'Xruntime-ja/doc/work2.jax')
  set rtp+=./Xruntime-ja

  help local-additions@en
  let lines = getline(line(".") + 1, search("^$") - 1)
  call assert_equal([
  \ '|mydoc.txt| my awesome doc'
  \ ], lines)
  close

  help local-additions@ja
  let lines = getline(line(".") + 1, search("^$") - 1)
  call assert_equal([
  \ '|mydoc.txt| my awesome doc',
  \ '|help.txt| This is jax file',
  \ '|work.txt| This is jax file',
  \ '|work2.txt| This is jax file',
  \ ], lines)
  close

  let &rtp = rtp_save
endfunc

func Test_help_completion()
  call feedkeys(":help :undo\<C-A>\<C-B>\"\<CR>", 'tx')
  call assert_equal('"help :undo :undoj :undol :undojoin :undolist', @:)
endfunc

" Test for the :helptags command
" NOTE: if you run tests as root this will fail.  Don't run tests as root!
func Test_helptag_cmd()
  call mkdir('Xtagdir/a/doc', 'pR')

  " No help file to process in the directory
  call assert_fails('helptags Xtagdir', 'E151:')

  call writefile([], 'Xtagdir/a/doc/sample.txt')

  " Test for ++t argument
  helptags ++t Xtagdir
  call assert_equal(["help-tags\ttags\t1"], readfile('Xtagdir/tags'))
  call delete('Xtagdir/tags')

  " Test parsing tags
  call writefile(['*tag1*', 'Example: >', '  *notag*', 'Example end: *tag2*'],
    \ 'Xtagdir/a/doc/sample.txt')
  helptags Xtagdir
  call assert_equal(["tag1\ta/doc/sample.txt\t/*tag1*",
                  \  "tag2\ta/doc/sample.txt\t/*tag2*"], readfile('Xtagdir/tags'))

  " Duplicate tags in the help file
  call writefile(['*tag1*', '*tag1*', '*tag2*'], 'Xtagdir/a/doc/sample.txt')
  call assert_fails('helptags Xtagdir', 'E154:')
endfunc

func Test_helptag_cmd_readonly()
  CheckUnix
  CheckNotRoot

  " Read-only tags file
  call mkdir('Xrodir/doc', 'pR')
  call writefile([''], 'Xrodir/doc/tags')
  call writefile([], 'Xrodir/doc/sample.txt')
  call setfperm('Xrodir/doc/tags', 'r-xr--r--')
  call assert_fails('helptags Xrodir/doc', 'E152:', getfperm('Xrodir/doc/tags'))

  let rtp = &rtp
  let &rtp = 'Xrodir'
  helptags ALL
  let &rtp = rtp

  call delete('Xrodir/doc/tags')

  " No permission to read the help file
  call mkdir('Xrodir/b/doc', 'p')
  call writefile([], 'Xrodir/b/doc/sample.txt')
  call setfperm('Xrodir/b/doc/sample.txt', '-w-------')
  call assert_fails('helptags Xrodir', 'E153:', getfperm('Xrodir/b/doc/sample.txt'))
endfunc

" Test for setting the 'helpheight' option in the help window
func Test_help_window_height()
  let &cmdheight = &lines - 23
  set helpheight=10
  help
  set helpheight=14
  call assert_equal(14, winheight(0))
  set helpheight& cmdheight=1
  close
endfunc

func Test_help_long_argument()
  try
    exe 'help \%' .. repeat('0', 1021)
  catch
    call assert_match("E149:", v:exception)
  endtry
endfunc

func Test_help_using_visual_match()
  let lines =<< trim END
      call setline(1, ' ')
      /^
      exe "normal \<C-V>\<C-V>"
      h5\%V€]
  END
  call v9.CheckScriptFailure(lines, 'E149:')
endfunc


" vim: shiftwidth=2 sts=2 expandtab