From 5dd6d0f8ff1681fff9369e0aa2532979954dbfde Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Wed, 20 Aug 2014 13:49:39 +0200

Subject: [PATCH] machine-id-setup: don't try to read UUID from VM/container

 manager if we operate on a root directory that's not /

This should make sure no UUID from the host systemd-machine-id-setup is

running on leaks onto a disk image that is provisioned with the tool.

---

 src/core/machine-id-setup.c | 79 +++++++++++++++++++++++----------------------

 1 file changed, 41 insertions(+), 38 deletions(-)

diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c

index 712f60cb11..efb074fcbd 100644

--- a/src/core/machine-id-setup.c

+++ b/src/core/machine-id-setup.c

@@ -64,15 +64,16 @@ static int generate(char id[34], const char *root) {

         int fd, r;

         unsigned char *p;

         sd_id128_t buf;

-        char *q;

+        char  *q;

         ssize_t k;

-        const char *vm_id;

-        _cleanup_free_ char *dbus_machine_id = NULL;

+        const char *vm_id, *dbus_machine_id;

         assert(id);

-        if (asprintf(&dbus_machine_id, "%s/var/lib/dbus/machine-id", root) < 0)

-                return log_oom();

+        if (isempty(root))

+                dbus_machine_id = "/var/lib/dbus/machine-id";

+        else

+                dbus_machine_id = strappenda(root, "/var/lib/dbus/machine-id");

         /* First, try reading the D-Bus machine id, unless it is a symlink */

         fd = open(dbus_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

@@ -93,46 +94,48 @@ static int generate(char id[34], const char *root) {

                 }

         }

-        /* If that didn't work, see if we are running in a container,

-         * and a machine ID was passed in via $container_uuid the way

-         * libvirt/LXC does it */

-        r = detect_container(NULL);

-        if (r > 0) {

-                _cleanup_free_ char *e = NULL;

-

-                r = getenv_for_pid(1, "container_uuid", &e);

+        if (isempty(root)) {

+                /* If that didn't work, see if we are running in a container,

+                 * and a machine ID was passed in via $container_uuid the way

+                 * libvirt/LXC does it */

+                r = detect_container(NULL);

                 if (r > 0) {

-                        if (strlen(e) >= 36) {

-                                r = shorten_uuid(id, e);

-                                if (r >= 0) {

-                                        log_info("Initializing machine ID from container UUID.");

-                                        return 0;

-                                }

-                        }

-                }

-

-        } else {

-                /* If we are not running in a container, see if we are

-                 * running in qemu/kvm and a machine ID was passed in

-                 * via -uuid on the qemu/kvm command line */

+                        _cleanup_free_ char *e = NULL;

-                r = detect_vm(&vm_id);

-                if (r > 0 && streq(vm_id, "kvm")) {

-                        char uuid[37];

-

-                        fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

-                        if (fd >= 0) {

-                                k = loop_read(fd, uuid, 36, false);

-                                safe_close(fd);

-

-                                if (k >= 36) {

-                                        r = shorten_uuid(id, uuid);

+                        r = getenv_for_pid(1, "container_uuid", &e);

+                        if (r > 0) {

+                                if (strlen(e) >= 36) {

+                                        r = shorten_uuid(id, e);

                                         if (r >= 0) {

-                                                log_info("Initializing machine ID from KVM UUID.");

+                                                log_info("Initializing machine ID from container UUID.");

                                                 return 0;

                                         }

                                 }

                         }

+

+                } else {

+                        /* If we are not running in a container, see if we are

+                         * running in qemu/kvm and a machine ID was passed in

+                         * via -uuid on the qemu/kvm command line */

+

+                        r = detect_vm(&vm_id);

+                        if (r > 0 && streq(vm_id, "kvm")) {

+                                char uuid[37];

+

+                                fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

+                                if (fd >= 0) {

+                                        k = loop_read(fd, uuid, 36, false);

+                                        safe_close(fd);

+

+                                        if (k >= 36) {

+                                                r = shorten_uuid(id, uuid);

+                                                if (r >= 0) {

+                                                        log_info("Initializing machine ID from KVM UUID.");

+                                                        return 0;

+                                                }

+                                        }

+                                }

+                        }

                 }

         }