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- add-canonicalize_path_restricted.patch,

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mount-sanitize-paths-from-non-root-users.patch,
  umount-sanitize-paths-from-non-root-users.patch:
  prevent leaking information about existence of folders
  (bnc#797002, CVE-2013-0157)

OBS-URL: https://build.opensuse.org/package/show/Base:System/util-linux?expand=0&rev=150
This commit is contained in:
Petr Uzel 2013-01-07 13:47:48 +00:00 committed by Git OBS Bridge
parent 168e109a16
commit b30522c80d
5 changed files with 285 additions and 4 deletions
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78
add-canonicalize_path_restricted.patch Normal file
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@ -0,0 +1,78 @@
From 33c5fd0c5a774458470c86f9d318d8c48a9c9ccb Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 26 Nov 2012 16:24:28 +0100
Subject: [PATCH] lib/canonicalize: add canonicalize_path_restricted() to
canonicalize without suid permisssions
Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
---
include/canonicalize.h | 1 +
lib/canonicalize.c | 42 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+)
Index: util-linux-2.21.2/include/canonicalize.h
===================================================================
--- util-linux-2.21.2.orig/include/canonicalize.h
+++ util-linux-2.21.2/include/canonicalize.h
@@ -4,6 +4,7 @@
#include "c.h" /* for PATH_MAX */
extern char *canonicalize_path(const char *path);
+extern char *canonicalize_path_restricted(const char *path);
extern char *canonicalize_dm_name(const char *ptname);
#endif /* CANONICALIZE_H */
Index: util-linux-2.21.2/lib/canonicalize.c
===================================================================
--- util-linux-2.21.2.orig/lib/canonicalize.c
+++ util-linux-2.21.2/lib/canonicalize.c
@@ -188,6 +188,48 @@ canonicalize_path(const char *path)
return strdup(canonical);
}
+char *
+canonicalize_path_restricted(const char *path)
+{
+ char canonical[PATH_MAX+2];
+ char *p = NULL;
+ int errsv;
+ uid_t euid;
+ gid_t egid;
+
+ if (path == NULL)
+ return NULL;
+
+ euid = geteuid();
+ egid = getegid();
+
+ /* drop permissions */
+ if (setegid(getgid()) < 0 || seteuid(getuid()) < 0)
+ return NULL;
+
+ errsv = errno = 0;
+
+ if (myrealpath(path, canonical, PATH_MAX+1)) {
+ p = strrchr(canonical, '/');
+ if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4)))
+ p = canonicalize_dm_name(p+1);
+ else
+ p = NULL;
+ if (!p)
+ p = strdup(canonical);
+ } else
+ errsv = errno;
+
+ /* restore */
+ if (setegid(egid) < 0 || seteuid(euid) < 0) {
+ free(p);
+ return NULL;
+ }
+
+ errno = errsv;
+ return p;
+}
+
#ifdef TEST_PROGRAM_CANONICALIZE
int main(int argc, char **argv)

102
mount-sanitize-paths-from-non-root-users.patch Normal file
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@ -0,0 +1,102 @@
From 5ebbc3865d1e53ef42e5f121c41faab23dd59075 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 26 Nov 2012 14:30:22 +0100
Subject: [PATCH] mount: sanitize paths from non-root users
$ mount /root/.ssh/../../dev/sda2
mount: only root can mount UUID=17bc65ec-4125-4e7c-8a7d-e2795064c736 on /boot
this is too promiscuous. It seems better to ignore on command line
specified paths which are not resolve-able for non-root users.
Fixed version:
$ mount /root/.ssh/../../dev/sda2
mount: /root/.ssh/../../dev/sda2: Permission denied
$ mount /dev/sda2
mount: only root can mount UUID=17bc65ec-4125-4e7c-8a7d-e2795064c736 on /boot
Note that this bug has no relation to mount(2) permissions evaluation
in suid mode. The way how non-root user specifies paths on command
line is completely irrelevant for comparison with fstab entries.
Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
---
sys-utils/Makefile.am | 1 +
sys-utils/mount.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
Index: util-linux-2.21.2/sys-utils/Makefile.am
===================================================================
--- util-linux-2.21.2.orig/sys-utils/Makefile.am
+++ util-linux-2.21.2/sys-utils/Makefile.am
@@ -64,6 +64,7 @@ dist_man_MANS += mount.8 ../mount/fstab.
mount_SOURCES = mount.c \
$(top_srcdir)/lib/env.c \
$(top_srcdir)/lib/xgetpass.c \
+ $(top_srcdir)/lib/canonicalize.c \
$(top_srcdir)/lib/strutils.c
mount_LDADD = $(ul_libmount_la) $(SELINUX_LIBS)
Index: util-linux-2.21.2/sys-utils/mount.c
===================================================================
--- util-linux-2.21.2.orig/sys-utils/mount.c
+++ util-linux-2.21.2/sys-utils/mount.c
@@ -38,6 +38,7 @@
#include "strutils.h"
#include "exitcodes.h"
#include "xalloc.h"
+#include "canonicalize.h"
/*** TODO: DOCS:
*
@@ -572,6 +573,37 @@ static struct libmnt_table *append_fstab
return fstab;
}
+/*
+ * Check source and target paths -- non-root user should not be able to
+ * resolve paths which are unreadable for him.
+ */
+static void sanitize_paths(struct libmnt_context *cxt)
+{
+ const char *p;
+ struct libmnt_fs *fs = mnt_context_get_fs(cxt);
+
+ if (!fs)
+ return;
+
+ p = mnt_fs_get_target(fs);
+ if (p) {
+ char *np = canonicalize_path_restricted(p);
+ if (!np)
+ err(MOUNT_EX_USAGE, "%s", p);
+ mnt_fs_set_target(fs, np);
+ free(np);
+ }
+
+ p = mnt_fs_get_srcpath(fs);
+ if (p) {
+ char *np = canonicalize_path_restricted(p);
+ if (!np)
+ err(MOUNT_EX_USAGE, "%s", p);
+ mnt_fs_set_source(fs, np);
+ free(np);
+ }
+}
+
static void __attribute__((__noreturn__)) usage(FILE *out)
{
fputs(USAGE_HEADER, out);
@@ -880,6 +912,9 @@ int main(int argc, char **argv)
} else
usage(stderr);
+ if (mnt_context_is_restricted(cxt))
+ sanitize_paths(cxt);
+
if (oper) {
/* MS_PROPAGATION operations, let's set the mount flags */
mnt_context_set_mflags(cxt, oper);

84
umount-sanitize-paths-from-non-root-users.patch Normal file
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@ -0,0 +1,84 @@
From cc8cc8f32c863f3ae6a8a88e97b47bcd6a21825f Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 26 Nov 2012 16:25:46 +0100
Subject: [PATCH] umount: sanitize paths from non-root users
Signed-off-by: Karel Zak <kzak@redhat.com>
Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
---
sys-utils/Makefile.am | 4 +++-
sys-utils/umount.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 33 insertions(+), 3 deletions(-)
Index: util-linux-2.21.2/sys-utils/Makefile.am
===================================================================
--- util-linux-2.21.2.orig/sys-utils/Makefile.am
+++ util-linux-2.21.2/sys-utils/Makefile.am
@@ -71,7 +71,9 @@ mount_LDADD = $(ul_libmount_la) $(SELINU
mount_CFLAGS = $(SUID_CFLAGS) $(AM_CFLAGS) -I$(ul_libmount_incdir)
mount_LDFLAGS = $(SUID_LDFLAGS) $(AM_LDFLAGS)
-umount_SOURCES = umount.c $(top_srcdir)/lib/env.c
+umount_SOURCES = umount.c \
+ $(top_srcdir)/lib/env.c \
+ $(top_srcdir)/lib/canonicalize.c
umount_LDADD = $(ul_libmount_la)
umount_CFLAGS = $(AM_CFLAGS) $(SUID_CFLAGS) -I$(ul_libmount_incdir)
umount_LDFLAGS = $(SUID_LDFLAGS) $(AM_LDFLAGS)
Index: util-linux-2.21.2/sys-utils/umount.c
===================================================================
--- util-linux-2.21.2.orig/sys-utils/umount.c
+++ util-linux-2.21.2/sys-utils/umount.c
@@ -34,6 +34,7 @@
#include "env.h"
#include "optutils.h"
#include "exitcodes.h"
+#include "canonicalize.h"
static int table_parser_errcb(struct libmnt_table *tb __attribute__((__unused__)),
const char *filename, int line)
@@ -277,6 +278,24 @@ static int umount_one(struct libmnt_cont
return rc;
}
+/*
+ * Check path -- non-root user should not be able to resolve path which is
+ * unreadable for him.
+ */
+static char *sanitize_path(const char *path)
+{
+ char *p;
+
+ if (!path)
+ return NULL;
+
+ p = canonicalize_path_restricted(path);
+ if (!p)
+ err(MOUNT_EX_USAGE, "%s", path);
+
+ return p;
+}
+
int main(int argc, char **argv)
{
int c, rc = 0, all = 0;
@@ -388,8 +407,17 @@ int main(int argc, char **argv)
} else if (argc < 1) {
usage(stderr);
- } else while (argc--)
- rc += umount_one(cxt, *argv++);
+ } else while (argc--) {
+ char *path = *argv++;
+
+ if (mnt_context_is_restricted(cxt))
+ path = sanitize_path(path);
+
+ rc += umount_one(cxt, path);
+
+ if (mnt_context_is_restricted(cxt))
+ free(path);
+ }
mnt_free_context(cxt);
return rc;

9
util-linux.changes
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@ -1,3 +1,12 @@
-------------------------------------------------------------------
Mon Jan 7 13:26:15 UTC 2013 - puzel@suse.com
- add-canonicalize_path_restricted.patch,
mount-sanitize-paths-from-non-root-users.patch,
umount-sanitize-paths-from-non-root-users.patch:
prevent leaking information about existence of folders
(bnc#797002, CVE-2013-0157)
-------------------------------------------------------------------
Fri Dec 28 04:30:58 UTC 2012 - crrodriguez@opensuse.org

16
util-linux.spec
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@ -1,7 +1,7 @@
#
# spec file for package util-linux
#
# Copyright (c) 2012 SUSE LINUX Products GmbH, Nuernberg, Germany.
# Copyright (c) 2013 SUSE LINUX Products GmbH, Nuernberg, Germany.
#
# All modifications and additions to the file contributed by third parties
# remain the property of their copyright owners, unless otherwise agreed
@ -106,6 +106,13 @@ Patch13: login-close-tty-before-vhangup.patch
# hack for boot.localfs
Patch20: util-linux-HACK-boot.localfs.diff
Patch21: 0001-include-bitops.h-Use-the-operating-system-byteswappi.patch
#bnc#797002
Patch22: add-canonicalize_path_restricted.patch
Patch23: mount-sanitize-paths-from-non-root-users.patch
Patch24: umount-sanitize-paths-from-non-root-users.patch
#####
##
@ -121,8 +128,6 @@ Patch56: klogconsole.diff
##
Patch60: time-1.7.dif
Patch61: 0001-include-bitops.h-Use-the-operating-system-byteswappi.patch
BuildRoot: %{_tmppath}/%{name}-%{version}-build
PreReq: %insserv_prereq %fillup_prereq /bin/sed
#
@ -223,7 +228,10 @@ Files to develop applications using the libmount library.
%patch13 -p1
#
%patch20 -p1
%patch61 -p1
%patch21 -p1
%patch22 -p1
%patch23 -p1
%patch24 -p1
#
cd adjtimex-*
# adjtimex patches belongs here