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forked from pool/util-linux
util-linux/mount-sanitize-paths-from-non-root-users.patch
Stephan Kulow 034a75e444 Accepting request 147398 from Base:System
- 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)

OBS-URL: https://build.opensuse.org/request/show/147398
OBS-URL: https://build.opensuse.org/package/show/openSUSE:Factory/util-linux?expand=0&rev=154
2013-01-08 14:05:08 +00:00

103 lines
2.9 KiB
Diff

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);