diff -up patch-2.7.6/src/pch.c.CVE-2018-1000156 patch-2.7.6/src/pch.c --- patch-2.7.6/src/pch.c.CVE-2018-1000156 2018-02-03 12:41:49.000000000 +0000 +++ patch-2.7.6/src/pch.c 2018-05-03 12:50:43.374036905 +0100 @@ -33,6 +33,7 @@ # include #endif #include +#include #define INITHUNKMAX 125 /* initial dynamic allocation size */ @@ -2388,22 +2389,28 @@ do_ed_script (char const *inname, char c static char const editor_program[] = EDITOR_PROGRAM; file_offset beginning_of_this_line; - FILE *pipefp = 0; size_t chars_read; + FILE *tmpfp = 0; + char const *tmpname; + int tmpfd = -1; + pid_t pid; + + if (! dry_run && ! skip_rest_of_patch) + { + /* Write ed script to a temporary file. This causes ed to abort on + invalid commands such as when line numbers or ranges exceed the + number of available lines. When ed reads from a pipe, it rejects + invalid commands and treats the next line as a new command, which + can lead to arbitrary command execution. */ + + tmpfd = make_tempfile (&tmpname, 'e', NULL, O_RDWR | O_BINARY, 0); + if (tmpfd == -1) + pfatal ("Can't create temporary file %s", quotearg (tmpname)); + tmpfp = fdopen (tmpfd, "w+b"); + if (! tmpfp) + pfatal ("Can't open stream for file %s", quotearg (tmpname)); + } - if (! dry_run && ! skip_rest_of_patch) { - int exclusive = *outname_needs_removal ? 0 : O_EXCL; - assert (! inerrno); - *outname_needs_removal = true; - copy_file (inname, outname, 0, exclusive, instat.st_mode, true); - sprintf (buf, "%s %s%s", editor_program, - verbosity == VERBOSE ? "" : "- ", - outname); - fflush (stdout); - pipefp = popen(buf, binary_transput ? "wb" : "w"); - if (!pipefp) - pfatal ("Can't open pipe to %s", quotearg (buf)); - } for (;;) { char ed_command_letter; beginning_of_this_line = file_tell (pfp); @@ -2414,14 +2421,14 @@ do_ed_script (char const *inname, char c } ed_command_letter = get_ed_command_letter (buf); if (ed_command_letter) { - if (pipefp) - if (! fwrite (buf, sizeof *buf, chars_read, pipefp)) + if (tmpfp) + if (! fwrite (buf, sizeof *buf, chars_read, tmpfp)) write_fatal (); if (ed_command_letter != 'd' && ed_command_letter != 's') { p_pass_comments_through = true; while ((chars_read = get_line ()) != 0) { - if (pipefp) - if (! fwrite (buf, sizeof *buf, chars_read, pipefp)) + if (tmpfp) + if (! fwrite (buf, sizeof *buf, chars_read, tmpfp)) write_fatal (); if (chars_read == 2 && strEQ (buf, ".\n")) break; @@ -2434,13 +2441,50 @@ do_ed_script (char const *inname, char c break; } } - if (!pipefp) + if (!tmpfp) return; - if (fwrite ("w\nq\n", sizeof (char), (size_t) 4, pipefp) == 0 - || fflush (pipefp) != 0) + if (fwrite ("w\nq\n", sizeof (char), (size_t) 4, tmpfp) == 0 + || fflush (tmpfp) != 0) write_fatal (); - if (pclose (pipefp) != 0) - fatal ("%s FAILED", editor_program); + + if (lseek (tmpfd, 0, SEEK_SET) == -1) + pfatal ("Can't rewind to the beginning of file %s", quotearg (tmpname)); + + if (! dry_run && ! skip_rest_of_patch) { + int exclusive = *outname_needs_removal ? 0 : O_EXCL; + *outname_needs_removal = true; + if (inerrno != ENOENT) + { + *outname_needs_removal = true; + copy_file (inname, outname, 0, exclusive, instat.st_mode, true); + } + sprintf (buf, "%s %s%s", editor_program, + verbosity == VERBOSE ? "" : "- ", + outname); + fflush (stdout); + + pid = fork(); + if (pid == -1) + pfatal ("Can't fork"); + else if (pid == 0) + { + dup2 (tmpfd, 0); + execl ("/bin/sh", "sh", "-c", buf, (char *) 0); + _exit (2); + } + else + { + int wstatus; + if (waitpid (pid, &wstatus, 0) == -1 + || ! WIFEXITED (wstatus) + || WEXITSTATUS (wstatus) != 0) + fatal ("%s FAILED", editor_program); + } + } + + fclose (tmpfp); + unlink (tmpname); + free((char*) tmpname); if (ofp) { diff -up patch-2.7.6/tests/ed-style.CVE-2018-1000156 patch-2.7.6/tests/ed-style --- patch-2.7.6/tests/ed-style.CVE-2018-1000156 2018-05-03 12:50:28.988937938 +0100 +++ patch-2.7.6/tests/ed-style 2018-05-03 12:51:35.841397873 +0100 @@ -0,0 +1,40 @@ +# Copyright (C) 2018 Free Software Foundation, Inc. +# +# Copying and distribution of this file, with or without modification, +# in any medium, are permitted without royalty provided the copyright +# notice and this notice are preserved. + +. $srcdir/test-lib.sh + +require_cat +use_local_patch +use_tmpdir + +# ============================================================== + +cat > ed1.diff < ed2.diff < /dev/null 2> /dev/null || echo "Status: $?"' <