[Spice-devel] [PATCH] usbredirparser: prevent endless recursion if interface_count == 0

[Alon Levy]

On fedora 24 this function is tail optimized, resulting in a busy wait.

This happens to me with virt-manager running a win7 vm 

usbredir-0.7.1-2.fc24.x86_64
---
Hi Guys!

 One liner to fix an issue I had with virt-manager - symptom is 100% cpu
 taken in it, stack traced to the problem fixed by this patch.

Alon

 usbredirparser/usbredirfilter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usbredirparser/usbredirfilter.c
b/usbredirparser/usbredirfilter.c
index 02184ef..bdfbfc2 100644
--- a/usbredirparser/usbredirfilter.c
+++ b/usbredirparser/usbredirfilter.c
@@ -205,7 +205,7 @@ int usbredirfilter_check(
      * by recursively calling this function with a flag that forbids
      * skipping (usbredirfilter_fl_dont_skip_non_boot_hid)
      */
-    if (num_skipped == interface_count) {
+    if (interface_count > 0 && num_skipped == interface_count) {
         rc = usbredirfilter_check(rules, rules_count,
                                   device_class, device_subclass,
                                   device_protocol,
                                   interface_class, interface_subclass,
-- 
2.7.4