b30522c80d
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
103 lines
2.9 KiB
Diff
103 lines
2.9 KiB
Diff
From 5ebbc3865d1e53ef42e5f121c41faab23dd59075 Mon Sep 17 00:00:00 2001
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From: Karel Zak <kzak@redhat.com>
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Date: Mon, 26 Nov 2012 14:30:22 +0100
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Subject: [PATCH] mount: sanitize paths from non-root users
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$ mount /root/.ssh/../../dev/sda2
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mount: only root can mount UUID=17bc65ec-4125-4e7c-8a7d-e2795064c736 on /boot
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this is too promiscuous. It seems better to ignore on command line
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specified paths which are not resolve-able for non-root users.
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Fixed version:
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$ mount /root/.ssh/../../dev/sda2
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mount: /root/.ssh/../../dev/sda2: Permission denied
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$ mount /dev/sda2
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mount: only root can mount UUID=17bc65ec-4125-4e7c-8a7d-e2795064c736 on /boot
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Note that this bug has no relation to mount(2) permissions evaluation
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in suid mode. The way how non-root user specifies paths on command
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line is completely irrelevant for comparison with fstab entries.
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Signed-off-by: Karel Zak <kzak@redhat.com>
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Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
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---
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sys-utils/Makefile.am | 1 +
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sys-utils/mount.c | 35 +++++++++++++++++++++++++++++++++++
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2 files changed, 36 insertions(+)
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Index: util-linux-2.21.2/sys-utils/Makefile.am
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===================================================================
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--- util-linux-2.21.2.orig/sys-utils/Makefile.am
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+++ util-linux-2.21.2/sys-utils/Makefile.am
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@@ -64,6 +64,7 @@ dist_man_MANS += mount.8 ../mount/fstab.
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mount_SOURCES = mount.c \
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$(top_srcdir)/lib/env.c \
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$(top_srcdir)/lib/xgetpass.c \
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+ $(top_srcdir)/lib/canonicalize.c \
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$(top_srcdir)/lib/strutils.c
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mount_LDADD = $(ul_libmount_la) $(SELINUX_LIBS)
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Index: util-linux-2.21.2/sys-utils/mount.c
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===================================================================
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--- util-linux-2.21.2.orig/sys-utils/mount.c
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+++ util-linux-2.21.2/sys-utils/mount.c
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@@ -38,6 +38,7 @@
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#include "strutils.h"
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#include "exitcodes.h"
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#include "xalloc.h"
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+#include "canonicalize.h"
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/*** TODO: DOCS:
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*
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@@ -572,6 +573,37 @@ static struct libmnt_table *append_fstab
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return fstab;
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}
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+/*
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+ * Check source and target paths -- non-root user should not be able to
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+ * resolve paths which are unreadable for him.
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+ */
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+static void sanitize_paths(struct libmnt_context *cxt)
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+{
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+ const char *p;
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+ struct libmnt_fs *fs = mnt_context_get_fs(cxt);
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+
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+ if (!fs)
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+ return;
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+
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+ p = mnt_fs_get_target(fs);
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+ if (p) {
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+ char *np = canonicalize_path_restricted(p);
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+ if (!np)
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+ err(MOUNT_EX_USAGE, "%s", p);
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+ mnt_fs_set_target(fs, np);
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+ free(np);
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+ }
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+
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+ p = mnt_fs_get_srcpath(fs);
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+ if (p) {
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+ char *np = canonicalize_path_restricted(p);
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+ if (!np)
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+ err(MOUNT_EX_USAGE, "%s", p);
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+ mnt_fs_set_source(fs, np);
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+ free(np);
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+ }
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+}
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+
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static void __attribute__((__noreturn__)) usage(FILE *out)
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{
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fputs(USAGE_HEADER, out);
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@@ -880,6 +912,9 @@ int main(int argc, char **argv)
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} else
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usage(stderr);
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+ if (mnt_context_is_restricted(cxt))
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+ sanitize_paths(cxt);
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+
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if (oper) {
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/* MS_PROPAGATION operations, let's set the mount flags */
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mnt_context_set_mflags(cxt, oper);
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