@@ -365,6 +365,24 @@ int libxl__domain_device_construct_rdm(libxl__gc *gc,
return ERROR_FAIL;
}
+/* XSA-180 / CVE-2014-3672
+ *
+ * The QEMU shipped with Xen has a bodge. It checks for
+ * XEN_QEMU_CONSOLE_LIMIT to see how much data QEMU is allowed
+ * to write to stderr. We set that to 1MB if it is not set by
+ * system administrator.
+ */
+static void libxl__set_qemu_env_for_xsa_180(libxl__gc *gc,
+ flexarray_t *dm_envs)
+{
+ unsigned long limit = 0;
+ const char *s = getenv("XEN_QEMU_CONSOLE_LIMIT");
+
+ limit = s ? strtoul(s,0,0) : 1*1024*1024;
+ flexarray_append_pair(dm_envs, "XEN_QEMU_CONSOLE_LIMIT",
+ GCSPRINTF("%lu", limit));
+}
+
const libxl_vnc_info *libxl__dm_vnc(const libxl_domain_config *guest_config)
{
const libxl_vnc_info *vnc = NULL;
@@ -415,6 +433,8 @@ static int libxl__build_device_model_args_old(libxl__gc *gc,
dm_args = flexarray_make(gc, 16, 1);
dm_envs = flexarray_make(gc, 16, 1);
+ libxl__set_qemu_env_for_xsa_180(gc, dm_envs);
+
flexarray_vappend(dm_args, dm,
"-d", GCSPRINTF("%d", domid), NULL);
@@ -913,6 +933,8 @@ static int libxl__build_device_model_args_new(libxl__gc *gc,
dm_args = flexarray_make(gc, 16, 1);
dm_envs = flexarray_make(gc, 16, 1);
+ libxl__set_qemu_env_for_xsa_180(gc, dm_envs);
+
flexarray_vappend(dm_args, dm,
"-xen-domid",
GCSPRINTF("%d", guest_domid), NULL);
@@ -2193,8 +2215,8 @@ static void device_model_spawn_outcome(libxl__egc *egc,
void libxl__spawn_qdisk_backend(libxl__egc *egc, libxl__dm_spawn_state *dmss)
{
STATE_AO_GC(dmss->spawn.ao);
- flexarray_t *dm_args;
- char **args;
+ flexarray_t *dm_args, *dm_envs;
+ char **args, **envs;
const char *dm;
int logfile_w, null = -1, rc;
uint32_t domid = dmss->guest_domid;
@@ -2203,6 +2225,8 @@ void libxl__spawn_qdisk_backend(libxl__egc *egc, libxl__dm_spawn_state *dmss)
dm = qemu_xen_path(gc);
dm_args = flexarray_make(gc, 15, 1);
+ dm_envs = flexarray_make(gc, 1, 1);
+
flexarray_vappend(dm_args, dm, "-xen-domid",
GCSPRINTF("%d", domid), NULL);
flexarray_append(dm_args, "-xen-attach");
@@ -2216,6 +2240,9 @@ void libxl__spawn_qdisk_backend(libxl__egc *egc, libxl__dm_spawn_state *dmss)
flexarray_append(dm_args, NULL);
args = (char **) flexarray_contents(dm_args);
+ libxl__set_qemu_env_for_xsa_180(gc, dm_envs);
+ envs = (char **) flexarray_contents(dm_envs);
+
logfile_w = libxl__create_qemu_logfile(gc, GCSPRINTF("qdisk-%u", domid));
if (logfile_w < 0) {
rc = logfile_w;
@@ -2253,7 +2280,7 @@ void libxl__spawn_qdisk_backend(libxl__egc *egc, libxl__dm_spawn_state *dmss)
goto out;
if (!rc) { /* inner child */
setsid();
- libxl__exec(gc, null, logfile_w, logfile_w, dm, args, NULL);
+ libxl__exec(gc, null, logfile_w, logfile_w, dm, args, envs);
}
rc = 0;
XSA-180 provides a patch to QEMU to bodge QEMU logging issue. We explicitly set the limit in libxl for 4.7. Introduce a function for setting the environment variable and call it in the right places. Signed-off-by: Wei Liu <wei.liu2@citrix.com> --- tools/libxl/libxl_dm.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-)