From 19599883ffb6a450d2884f081f8ecf68edbed7ee Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Thu, 3 May 2018 14:31:55 +0200 Subject: [PATCH 14/17] Don't leak temporary file on failed ed-style patch Now that we write ed-style patches to a temporary file before we apply them, we need to ensure that the temporary file is removed before we leave, even on fatal error. * src/pch.c (do_ed_script): Use global TMPEDNAME instead of local tmpname. Don't unlink the file directly, instead tag it for removal at exit time. * src/patch.c (cleanup): Unlink TMPEDNAME at exit. This closes bug #53820: https://savannah.gnu.org/bugs/index.php?53820 Fixes: 123eaff0d5d1 ("Fix arbitrary command execution in ed-style patches (CVE-2018-1000156)") --- src/common.h | 2 ++ src/patch.c | 1 + src/pch.c | 11 +++++------ 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/src/common.h b/src/common.h index 904a3f8..53c5e32 100644 --- a/src/common.h +++ b/src/common.h @@ -94,10 +94,12 @@ XTERN char const *origsuff; XTERN char const * TMPINNAME; XTERN char const * TMPOUTNAME; XTERN char const * TMPPATNAME; +XTERN char const * TMPEDNAME; XTERN bool TMPINNAME_needs_removal; XTERN bool TMPOUTNAME_needs_removal; XTERN bool TMPPATNAME_needs_removal; +XTERN bool TMPEDNAME_needs_removal; #ifdef DEBUGGING XTERN int debug; diff --git a/src/patch.c b/src/patch.c index 3fcaec5..9146597 100644 --- a/src/patch.c +++ b/src/patch.c @@ -1999,6 +1999,7 @@ cleanup (void) remove_if_needed (TMPINNAME, &TMPINNAME_needs_removal); remove_if_needed (TMPOUTNAME, &TMPOUTNAME_needs_removal); remove_if_needed (TMPPATNAME, &TMPPATNAME_needs_removal); + remove_if_needed (TMPEDNAME, &TMPEDNAME_needs_removal); remove_if_needed (TMPREJNAME, &TMPREJNAME_needs_removal); output_files (NULL); } diff --git a/src/pch.c b/src/pch.c index 79a3c99..1bb3153 100644 --- a/src/pch.c +++ b/src/pch.c @@ -2411,12 +2410,13 @@ do_ed_script (char const *inname, char const *outname, 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); + tmpfd = make_tempfile (&TMPEDNAME, 'e', NULL, O_RDWR | O_BINARY, 0); if (tmpfd == -1) - pfatal ("Can't create temporary file %s", quotearg (tmpname)); + pfatal ("Can't create temporary file %s", quotearg (TMPEDNAME)); + TMPEDNAME_needs_removal = true; tmpfp = fdopen (tmpfd, "w+b"); if (! tmpfp) - pfatal ("Can't open stream for file %s", quotearg (tmpname)); + pfatal ("Can't open stream for file %s", quotearg (TMPEDNAME)); } for (;;) { @@ -2457,7 +2457,7 @@ do_ed_script (char const *inname, char const *outname, write_fatal (); if (lseek (tmpfd, 0, SEEK_SET) == -1) - pfatal ("Can't rewind to the beginning of file %s", quotearg (tmpname)); + pfatal ("Can't rewind to the beginning of file %s", quotearg (TMPEDNAME)); if (inerrno != ENOENT) { @@ -2484,7 +2484,6 @@ do_ed_script (char const *inname, char const *outname, pfatal ("Failed to duplicate standard input"); fclose (tmpfp); - safe_unlink (tmpname); if (ofp) { -- 2.11.0