tools/sed/patches/001-sed-fix-handling-of-symlinks-pointing-to-path-with-1.patch

   1 From 8f600f2df293d539e9e9137f6f82faa1633b97c1 Mon Sep 17 00:00:00 2001
   2 From: Paul Eggert <eggert@cs.ucla.edu>
   3 Date: Sat, 17 Dec 2022 20:56:29 -0800
   4 Subject: [PATCH] sed: fix symlink bufsize readlink check
   5
   6 Problem reported by Hauke Mehrtens.
   7 * sed/utils.c (follow_symlink): Fix typo when checking size of
   8 second and later symlink, when that symlink is so large that it
   9 does not fit into the buffer.  Although the bug is not a buffer
  10 overflow, it does cause sed to mishandle the symlink.
  11 * testsuite/follow-symlinks.sh: Test for the bug.
  12 ---
  13  sed/utils.c                  |  2 +-
  14  testsuite/follow-symlinks.sh | 13 +++++++++++++
  15  3 files changed, 18 insertions(+), 1 deletion(-)
  16
  17 --- a/sed/utils.c
  18 +++ b/sed/utils.c
  19 @@ -345,7 +345,7 @@ follow_symlink (const char *fname)
  20        while ((linklen = (buf_used < buf_size
  21                           ? readlink (fn, buf + buf_used, buf_size - buf_used)
  22                           : 0))
  23 -             == buf_size)
  24 +             == buf_size - buf_used)
  25          {
  26            buf = xpalloc (buf, &buf_size, 1, SSIZE_IDX_MAX, 1);
  27            if (num_links)
  28 --- a/testsuite/follow-symlinks.sh
  29 +++ b/testsuite/follow-symlinks.sh
  30 @@ -73,4 +73,17 @@ compare_ exp-la-abs out-la-abs || fail=1
  31  ln -s la-loop la-loop || framework_failure_
  32  sed --follow-symlinks -i s/a/b/ la-loop && fail=1
  33
  34 +# symlink of length 128
  35 +long=d/
  36 +for i in 2 3 4 5 6 7; do
  37 +  long=$long$long
  38 +done
  39 +dir=${long%/d/}
  40 +file=$dir/xx
  41 +mkdir -p $dir &&
  42 +echo x >$file &&
  43 +ln -s $file yy &&
  44 +ln -s yy xx || framework_failure_
  45 +sed -i --follow-symlinks s/x/y/ xx || fail=1
  46 +
  47  Exit $fail