diff mbox series

[v6,18/18] libxl: Check stubdomain kernel & ramdisk presence

Message ID 20200518011353.326287-19-jandryuk@gmail.com (mailing list archive)
State Superseded
Headers show
Series Add support for qemu-xen runnning in a Linux-based stubdomain | expand

Commit Message

Jason Andryuk May 18, 2020, 1:13 a.m. UTC 
Just out of context is the following comment for libxl__domain_make:
/* fixme: this function can leak the stubdom if it fails */

When the stubdomain kernel or ramdisk is not present, the domid and
stubdomain name will indeed be leaked.  Avoid the leak by checking the
file presence and erroring out when absent.  It doesn't fix all cases,
but it avoids a big one when using a linux device model stubdomain.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

---
Changes in v6:
 - Add Acked-by: Ian Jackson
---
 tools/libxl/libxl_dm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
diff mbox series

Patch

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index 098dc49ecb..997c4815e0 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -2336,6 +2336,22 @@  void libxl__spawn_stub_dm(libxl__egc *egc, libxl__stub_dm_spawn_state *sdss)
         dm_config->num_vkbs = 1;
     }
 
+    if (guest_config->b_info.stubdomain_kernel &&
+        access(guest_config->b_info.stubdomain_kernel, R_OK) != 0) {
+        LOGED(ERROR, guest_domid, "could not access stubdomain kernel %s",
+              guest_config->b_info.stubdomain_kernel);
+        ret = ERROR_INVAL;
+        goto out;
+    }
+
+    if (guest_config->b_info.stubdomain_ramdisk &&
+        access(guest_config->b_info.stubdomain_ramdisk, R_OK) != 0) {
+        LOGED(ERROR, guest_domid, "could not access stubdomain ramdisk %s",
+              guest_config->b_info.stubdomain_ramdisk);
+        ret = ERROR_INVAL;
+        goto out;
+    }
+
     stubdom_state->pv_kernel.path = guest_config->b_info.stubdomain_kernel;
     stubdom_state->pv_ramdisk.path = guest_config->b_info.stubdomain_ramdisk;