From 76a62af5419dc652159daf68f31164c2ef0368d7 Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Tue, 3 May 2016 15:58:32 +0100 Subject: [PATCH] libxl: Do not trust frontend for vtpm list libxl_device_vtpm_list needs to enumerate and identify devices without trusting frontend-controlled data. So * Use the /libxl path to enumerate vtpms. * Use the /libxl path to find the corresponding backends. * Parse the backend path to find the backend domid. This is part of XSA-175. Signed-off-by: Ian Jackson Reviewed-by: Wei Liu --- tools/libxl/libxl.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 18f9f0a2cd..0886d92a5e 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -1879,14 +1879,15 @@ libxl_device_vtpm *libxl_device_vtpm_list(libxl_ctx *ctx, uint32_t domid, int *n GC_INIT(ctx); libxl_device_vtpm* vtpms = NULL; - char* fe_path = NULL; + char *libxl_path; char** dir = NULL; unsigned int ndirs = 0; + int rc; *num = 0; - fe_path = libxl__sprintf(gc, "%s/device/vtpm", libxl__xs_get_dompath(gc, domid)); - dir = libxl__xs_directory(gc, XBT_NULL, fe_path, &ndirs); + libxl_path = GCSPRINTF("%s/device/vtpm", libxl__xs_libxl_path(gc, domid)); + dir = libxl__xs_directory(gc, XBT_NULL, libxl_path, &ndirs); if (dir && ndirs) { vtpms = malloc(sizeof(*vtpms) * ndirs); libxl_device_vtpm* vtpm; @@ -1895,16 +1896,15 @@ libxl_device_vtpm *libxl_device_vtpm_list(libxl_ctx *ctx, uint32_t domid, int *n char* tmp; const char* be_path = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/%s/backend", - fe_path, *dir)); + libxl_path, *dir)); libxl_device_vtpm_init(vtpm); vtpm->devid = atoi(*dir); - tmp = libxl__xs_read(gc, XBT_NULL, - GCSPRINTF("%s/%s/backend-id", - fe_path, *dir)); - vtpm->backend_domid = atoi(tmp); + rc = libxl__backendpath_parse_domid(gc, be_path, + &vtpm->backend_domid); + if (rc) return NULL; tmp = libxl__xs_read(gc, XBT_NULL, GCSPRINTF("%s/uuid", be_path)); if (tmp) { -- 2.39.5