[PATCH] xen/iommu: dt: Check the return value of xsm_deassign_dtdevice()

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

xsm_deasign_dtdevice() will indicate whether the caller is allowed
to issue the operation. So the return value has to be checked.

Spotted by clang static analyzer.

Fixes: fe36cccc483c ("xen/passthrough: Extend XEN_DOMCTL_*assign_device to 
support DT device")
Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>

---

Platform device-passthrough is not security supported. Hence why this is
sent directly to xen-devel.
---
 xen/drivers/passthrough/device_tree.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/drivers/passthrough/device_tree.c 
b/xen/drivers/passthrough/device_tree.c
index 98f2aa0dad68..1c32d7b50cce 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -269,6 +269,8 @@ int iommu_do_dt_domctl(struct xen_domctl *domctl, struct 
domain *d,
             break;
 
         ret = xsm_deassign_dtdevice(XSM_HOOK, d, dt_node_full_name(dev));
+        if ( ret )
+            break;
 
         if ( d == dom_io )
             return -EINVAL;
-- 
2.32.0