3 files changed, 195 insertions, 64 deletions

diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh
index 0b86c47baf7d..2dccf141241d 100755
--- a/scripts/selinux/install_policy.sh
+++ b/scripts/selinux/install_policy.sh
@@ -1,30 +1,61 @@
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
+set -e
 if [ `id -u` -ne 0 ]; then
         echo "$0: must be root to install the selinux policy"
         exit 1
 fi
+
 SF=`which setfiles`
 if [ $? -eq 1 ]; then
-        if [ -f /sbin/setfiles ]; then
-                SF="/usr/setfiles"
-        else
-                echo "no selinux tools installed: setfiles"
-                exit 1
-        fi
+        echo "Could not find setfiles"
+        echo "Do you have policycoreutils installed?"
+        exit 1
 fi
 
-cd mdp
-
 CP=`which checkpolicy`
+if [ $? -eq 1 ]; then
+        echo "Could not find checkpolicy"
+        echo "Do you have checkpolicy installed?"
+        exit 1
+fi
 VERS=`$CP -V | awk '{print $1}'`
 
-./mdp policy.conf file_contexts
-$CP -o policy.$VERS policy.conf
+ENABLED=`which selinuxenabled`
+if [ $? -eq 1 ]; then
+        echo "Could not find selinuxenabled"
+        echo "Do you have libselinux-utils installed?"
+        exit 1
+fi
+
+if selinuxenabled; then
+    echo "SELinux is already enabled"
+    echo "This prevents safely relabeling all files."
+    echo "Boot with selinux=0 on the kernel command-line or"
+    echo "SELINUX=disabled in /etc/selinux/config."
+    exit 1
+fi
+
+cd mdp
+./mdp -m policy.conf file_contexts
+$CP -U allow -M -o policy.$VERS policy.conf
 
 mkdir -p /etc/selinux/dummy/policy
 mkdir -p /etc/selinux/dummy/contexts/files
 
+echo "__default__:user_u:s0" > /etc/selinux/dummy/seusers
+echo "base_r:base_t:s0" > /etc/selinux/dummy/contexts/failsafe_context
+echo "base_r:base_t:s0 base_r:base_t:s0" > /etc/selinux/dummy/default_contexts
+cat > /etc/selinux/dummy/contexts/x_contexts <<EOF
+client * user_u:base_r:base_t:s0
+property * user_u:object_r:base_t:s0
+extension * user_u:object_r:base_t:s0
+selection * user_u:object_r:base_t:s0
+event * user_u:object_r:base_t:s0
+EOF
+touch /etc/selinux/dummy/contexts/virtual_domain_context
+touch /etc/selinux/dummy/contexts/virtual_image_context
+
 cp file_contexts /etc/selinux/dummy/contexts/files
 cp dbus_contexts /etc/selinux/dummy/contexts
 cp policy.$VERS /etc/selinux/dummy/policy
@@ -33,37 +64,22 @@ FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts
 if [ ! -d /etc/selinux ]; then
         mkdir -p /etc/selinux
 fi
-if [ ! -f /etc/selinux/config ]; then
-        cat > /etc/selinux/config << EOF
-SELINUX=enforcing
+if [ -f /etc/selinux/config ]; then
+    echo "/etc/selinux/config exists, moving to /etc/selinux/config.bak."
+    mv /etc/selinux/config /etc/selinux/config.bak
+fi
+echo "Creating new /etc/selinux/config for dummy policy."
+cat > /etc/selinux/config << EOF
+SELINUX=permissive
 SELINUXTYPE=dummy
 EOF
-else
-        TYPE=`cat /etc/selinux/config | grep "^SELINUXTYPE" | tail -1 | awk -F= '{ print $2 '}`
-        if [ "eq$TYPE" != "eqdummy" ]; then
-                selinuxenabled
-                if [ $? -eq 0 ]; then
-                        echo "SELinux already enabled with a non-dummy policy."
-                        echo "Exiting.  Please install policy by hand if that"
-                        echo "is what you REALLY want."
-                        exit 1
-                fi
-                mv /etc/selinux/config /etc/selinux/config.mdpbak
-                grep -v "^SELINUXTYPE" /etc/selinux/config.mdpbak >> /etc/selinux/config
-                echo "SELINUXTYPE=dummy" >> /etc/selinux/config
-        fi
-fi
 
 cd /etc/selinux/dummy/contexts/files
-$SF file_contexts /
+$SF -F file_contexts /
 
-mounts=`cat /proc/$$/mounts | egrep "ext2|ext3|xfs|jfs|ext4|ext4dev|gfs2" | awk '{ print $2 '}`
-$SF file_contexts $mounts
+mounts=`cat /proc/$$/mounts | \
+        egrep "ext[234]|jfs|xfs|reiserfs|jffs2|gfs2|btrfs|f2fs|ocfs2" | \
+        awk '{ print $2 '}`
+$SF -F file_contexts $mounts
 
-
-dodev=`cat /proc/$$/mounts | grep "/dev "`
-if [ "eq$dodev" != "eq" ]; then
-        mount --move /dev /mnt
-        $SF file_contexts /dev
-        mount --move /mnt /dev
-fi
+echo "-F" > /.autorelabel
diff --git a/scripts/selinux/mdp/Makefile b/scripts/selinux/mdp/Makefile
index e9c92db7e2a3..8a1269a9d0ba 100644
--- a/scripts/selinux/mdp/Makefile
+++ b/scripts/selinux/mdp/Makefile
@@ -2,7 +2,7 @@
 hostprogs-y     := mdp
 HOST_EXTRACFLAGS += \
         -I$(srctree)/include/uapi -I$(srctree)/include \
-        -I$(srctree)/security/selinux/include
+        -I$(srctree)/security/selinux/include -I$(objtree)/include
 
 always          := $(hostprogs-y)
 clean-files     := policy.* file_contexts
diff --git a/scripts/selinux/mdp/mdp.c b/scripts/selinux/mdp/mdp.c
index 6d51b74bc679..18fd6143888b 100644
--- a/scripts/selinux/mdp/mdp.c
+++ b/scripts/selinux/mdp/mdp.c
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <linux/kconfig.h>
 
 static void usage(char *name)
 {
@@ -94,10 +95,31 @@ int main(int argc, char *argv[])
         }
         fprintf(fout, "\n");
 
-        /* NOW PRINT OUT MLS STUFF */
+        /* print out mls declarations and constraints */
         if (mls) {
-                printf("MLS not yet implemented\n");
-                exit(1);
+                fprintf(fout, "sensitivity s0;\n");
+                fprintf(fout, "sensitivity s1;\n");
+                fprintf(fout, "dominance { s0 s1 }\n");
+                fprintf(fout, "category c0;\n");
+                fprintf(fout, "category c1;\n");
+                fprintf(fout, "level s0:c0.c1;\n");
+                fprintf(fout, "level s1:c0.c1;\n");
+#define SYSTEMLOW "s0"
+#define SYSTEMHIGH "s1:c0.c1"
+                for (i = 0; secclass_map[i].name; i++) {
+                        struct security_class_mapping *map = &secclass_map[i];
+
+                        fprintf(fout, "mlsconstrain %s {\n", map->name);
+                        for (j = 0; map->perms[j]; j++)
+                                fprintf(fout, "\t%s\n", map->perms[j]);
+                        /*
+                         * This requires all subjects and objects to be
+                         * single-level (l2 eq h2), and that the subject
+                         * level dominate the object level (h1 dom h2)
+                         * in order to have any permissions to it.
+                         */
+                        fprintf(fout, "} (l2 eq h2 and h1 dom h2);\n\n");
+                }
         }
 
         /* types, roles, and allows */
@@ -107,34 +129,127 @@ int main(int argc, char *argv[])
         for (i = 0; secclass_map[i].name; i++)
                 fprintf(fout, "allow base_t base_t:%s *;\n",
                         secclass_map[i].name);
-        fprintf(fout, "user user_u roles { base_r };\n");
-        fprintf(fout, "\n");
+        fprintf(fout, "user user_u roles { base_r }");
+        if (mls)
+                fprintf(fout, " level %s range %s - %s", SYSTEMLOW,
+                        SYSTEMLOW, SYSTEMHIGH);
+        fprintf(fout, ";\n");
+
+#define SUBJUSERROLETYPE "user_u:base_r:base_t"
+#define OBJUSERROLETYPE "user_u:object_r:base_t"
 
         /* default sids */
         for (i = 1; i < initial_sid_to_string_len; i++)
-                fprintf(fout, "sid %s user_u:base_r:base_t\n", initial_sid_to_string[i]);
+                fprintf(fout, "sid %s " SUBJUSERROLETYPE "%s\n",
+                        initial_sid_to_string[i], mls ? ":" SYSTEMLOW : "");
         fprintf(fout, "\n");
 
-        fprintf(fout, "fs_use_xattr ext2 user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr ext3 user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr ext4 user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr jfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr xfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr reiserfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr jffs2 user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_xattr gfs2 user_u:base_r:base_t;\n");
+#define FS_USE(behavior, fstype)                            \
+        fprintf(fout, "fs_use_%s %s " OBJUSERROLETYPE "%s;\n", \
+                behavior, fstype, mls ? ":" SYSTEMLOW : "")
+
+        /*
+         * Filesystems whose inode labels can be fetched via getxattr.
+         */
+#ifdef CONFIG_EXT2_FS_SECURITY
+        FS_USE("xattr", "ext2");
+#endif
+#ifdef CONFIG_EXT4_FS_SECURITY
+#ifdef CONFIG_EXT4_USE_FOR_EXT2
+        FS_USE("xattr", "ext2");
+#endif
+        FS_USE("xattr", "ext3");
+        FS_USE("xattr", "ext4");
+#endif
+#ifdef CONFIG_JFS_SECURITY
+        FS_USE("xattr", "jfs");
+#endif
+#ifdef CONFIG_REISERFS_FS_SECURITY
+        FS_USE("xattr", "reiserfs");
+#endif
+#ifdef CONFIG_JFFS2_FS_SECURITY
+        FS_USE("xattr", "jffs2");
+#endif
+#ifdef CONFIG_XFS_FS
+        FS_USE("xattr", "xfs");
+#endif
+#ifdef CONFIG_GFS2_FS
+        FS_USE("xattr", "gfs2");
+#endif
+#ifdef CONFIG_BTRFS_FS
+        FS_USE("xattr", "btrfs");
+#endif
+#ifdef CONFIG_F2FS_FS_SECURITY
+        FS_USE("xattr", "f2fs");
+#endif
+#ifdef CONFIG_OCFS2_FS
+        FS_USE("xattr", "ocsfs2");
+#endif
+#ifdef CONFIG_OVERLAY_FS
+        FS_USE("xattr", "overlay");
+#endif
+#ifdef CONFIG_SQUASHFS_XATTR
+        FS_USE("xattr", "squashfs");
+#endif
+
+        /*
+         * Filesystems whose inodes are labeled from allocating task.
+         */
+        FS_USE("task", "pipefs");
+        FS_USE("task", "sockfs");
 
-        fprintf(fout, "fs_use_task eventpollfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_task pipefs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_task sockfs user_u:base_r:base_t;\n");
+        /*
+         * Filesystems whose inode labels are computed from both
+         * the allocating task and the superblock label.
+         */
+#ifdef CONFIG_UNIX98_PTYS
+        FS_USE("trans", "devpts");
+#endif
+#ifdef CONFIG_HUGETLBFS
+        FS_USE("trans", "hugetlbfs");
+#endif
+#ifdef CONFIG_TMPFS
+        FS_USE("trans", "tmpfs");
+#endif
+#ifdef CONFIG_DEVTMPFS
+        FS_USE("trans", "devtmpfs");
+#endif
+#ifdef CONFIG_POSIX_MQUEUE
+        FS_USE("trans", "mqueue");
+#endif
 
-        fprintf(fout, "fs_use_trans mqueue user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_trans devpts user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_trans hugetlbfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_trans tmpfs user_u:base_r:base_t;\n");
-        fprintf(fout, "fs_use_trans shm user_u:base_r:base_t;\n");
+#define GENFSCON(fstype, prefix)                             \
+        fprintf(fout, "genfscon %s %s " OBJUSERROLETYPE "%s\n", \
+                fstype, prefix, mls ? ":" SYSTEMLOW : "")
 
-        fprintf(fout, "genfscon proc / user_u:base_r:base_t\n");
+        /*
+         * Filesystems whose inodes are labeled from path prefix match
+         * relative to the filesystem root.  Depending on the filesystem,
+         * only a single label for all inodes may be supported.  Here
+         * we list the filesystem types for which per-file labeling is
+         * supported using genfscon; any other filesystem type can also
+         * be added by only with a single entry for all of its inodes.
+         */
+#ifdef CONFIG_PROC_FS
+        GENFSCON("proc", "/");
+#endif
+#ifdef CONFIG_SECURITY_SELINUX
+        GENFSCON("selinuxfs", "/");
+#endif
+#ifdef CONFIG_SYSFS
+        GENFSCON("sysfs", "/");
+#endif
+#ifdef CONFIG_DEBUG_FS
+        GENFSCON("debugfs", "/");
+#endif
+#ifdef CONFIG_TRACING
+        GENFSCON("tracefs", "/");
+#endif
+#ifdef CONFIG_PSTORE
+        GENFSCON("pstore", "/");
+#endif
+        GENFSCON("cgroup", "/");
+        GENFSCON("cgroup2", "/");
 
         fclose(fout);
 
@@ -143,8 +258,8 @@ int main(int argc, char *argv[])
                 printf("Wrote policy, but cannot open %s for writing\n", ctxout);
                 usage(argv[0]);
         }
-        fprintf(fout, "/ user_u:base_r:base_t\n");
-        fprintf(fout, "/.* user_u:base_r:base_t\n");
+        fprintf(fout, "/ " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : "");
+        fprintf(fout, "/.* " OBJUSERROLETYPE "%s\n", mls ? ":" SYSTEMLOW : "");
         fclose(fout);
 
         return 0;