rpms/patch
7
0
Fork 0
Code Issues Pull Requests Releases Activity

Fixed CVE-2018-1000156 - Malicious patch files cause ed to execute arbitrary commands.

Browse Source
This commit is contained in:
Tim Waugh 2018-05-03 12:53:39 +01:00
parent b0e48a7ada
commit 3aad41012c
No known key found for this signature in database
GPG Key ID: B7C20D079491EA63
2 changed files with 218 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

209
patch-CVE-2018-1000156.patch Normal file
View File

@ -0,0 +1,209 @@
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 <io.h>
#endif
#include <safe.h>
+#include <sys/wait.h>
#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 <<EOF
+0a
+foo
+.
+EOF
+
+check 'patch -e foo -i ed1.diff' <<EOF
+EOF
+
+check 'cat foo' <<EOF
+foo
+EOF
+
+cat > ed2.diff <<EOF
+1337a
+r !echo bar
+,p
+EOF
+
+check 'patch -e foo -i ed2.diff > /dev/null 2> /dev/null || echo "Status: $?"' <<EOF
+Status: 2
+EOF
+
+check 'cat foo' <<EOF
+foo
+EOF
diff -up patch-2.7.6/tests/Makefile.am.CVE-2018-1000156 patch-2.7.6/tests/Makefile.am
--- patch-2.7.6/tests/Makefile.am.CVE-2018-1000156 2018-05-03 12:50:28.988937938 +0100
+++ patch-2.7.6/tests/Makefile.am 2018-05-03 12:50:57.340132989 +0100
@@ -32,6 +32,7 @@ TESTS = \
crlf-handling \
dash-o-append \
deep-directories \
+ ed-style \
empty-files \
false-match \
fifo \
diff -up patch-2.7.6/tests/Makefile.in.CVE-2018-1000156 patch-2.7.6/tests/Makefile.in
--- patch-2.7.6/tests/Makefile.in.CVE-2018-1000156 2018-05-03 12:50:28.989937944 +0100
+++ patch-2.7.6/tests/Makefile.in 2018-05-03 12:51:25.974329992 +0100
@@ -1308,6 +1308,7 @@ TESTS = \
crlf-handling \
dash-o-append \
deep-directories \
+ ed-style \
empty-files \
false-match \
fifo \
@@ -1645,6 +1646,13 @@ empty-files.log: empty-files
$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
--log-file $$b.log --trs-file $$b.trs \
$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+ "$$tst" $(AM_TESTS_FD_REDIRECT)
+ed-style.log: empty-files
+ @p='ed-style'; \
+ b='ed-style'; \
+ $(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+ --log-file $$b.log --trs-file $$b.trs \
+ $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
"$$tst" $(AM_TESTS_FD_REDIRECT)
false-match.log: false-match
@p='false-match'; \

10
patch.spec
View File

@ -1,11 +1,12 @@
Summary: Utility for modifying/upgrading files
Name: patch
Version: 2.7.6
Release: 3%{?dist}
Release: 4%{?dist}
License: GPLv3+
URL: http://www.gnu.org/software/patch/patch.html
Group: Development/Tools
Source: ftp://ftp.gnu.org/gnu/patch/patch-%{version}.tar.xz
Patch1: patch-CVE-2018-1000156.patch
Patch100: patch-selinux.patch
Buildroot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@ -26,6 +27,9 @@ applications.
%prep
%setup -q
# CVE-2018-1000156, Malicious patch files cause ed to execute arbitrary commands
%patch1 -p1 -b .CVE-2018-1000156
# SELinux support.
%patch100 -p1 -b .selinux
@ -52,6 +56,10 @@ rm -rf $RPM_BUILD_ROOT
%{_mandir}/*/*
%changelog
* Thu May 3 2018 Tim Waugh <twaugh@redhat.com> - 2.7.6-4
- Fixed CVE-2018-1000156 - Malicious patch files cause ed to execute arbitrary
commands.
* Mon Feb 12 2018 Tim Waugh <twaugh@redhat.com> - 2.7.6-3
- 2.7.6 (CVE-2016-10713, CVE-2018-6951, CVE-2018-6952).