nspawn: add nosuid and nodev to /tmp mount (#6004)

When automatic /tmp mount was introduced to nspawn in v219, it was done without having the nosuid and nodev mount options, which was the same case as systemd's default tmp.mount unit back then.

nosuid and nodev was added to tmp.mount(.m4) in v231 for security reasons. matching the nspawn /tmp mount entry against that.

Ref.:
https://github.com/systemd/systemd/commit/2f9df7c96a25adb42093ee3ee201577f3e01da42
https://github.com/systemd/systemd/commit/bbb99c30d01a8bcdc27fb151cc6376a7877a6b07

diff --git a/src/nspawn/nspawn-mount.c b/src/nspawn/nspawn-mount.c
index d27699412070ea153ddc13b2bfd781422a06f488..ac7290732e58fdb1b0208d240ad58f9aa7e81a1a 100644 (file)
--- a/src/nspawn/nspawn-mount.c
+++ b/src/nspawn/nspawn-mount.c
@@ -552,7 +552,7 @@ int mount_all(const char *dest,
                 { NULL,                  "/proc/sysrq-trigger", NULL,    NULL,        MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT,             MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO },                          /* ... then, make it r/o */
 
                 /* outer child mounts */
-                { "tmpfs",               "/tmp",                "tmpfs", "mode=1777", MS_STRICTATIME,                                            MOUNT_FATAL },
+                { "tmpfs",               "/tmp",                "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME,                                            MOUNT_FATAL },
                 { "tmpfs",               "/sys",                "tmpfs", "mode=755",  MS_NOSUID|MS_NOEXEC|MS_NODEV,                              MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS },
                 { "sysfs",               "/sys",                "sysfs", NULL,        MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV,                    MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO },    /* skipped if above was mounted */
                 { "sysfs",               "/sys",                "sysfs", NULL,                  MS_NOSUID|MS_NOEXEC|MS_NODEV,                    MOUNT_FATAL },                          /* skipped if above was mounted */