lxc: Avoid segfault of libvirt_lxc helper on early cleanup paths

Early jumps to the cleanup label caused a crash of the libvirt_lxc
container helper as the cleanup section called
virLXCControllerDeleteInterfaces(ctrl) without checking the ctrl argument
for NULL. The argument was de-referenced soon after.

$ /usr/libexec/libvirt_lxc
/usr/libexec/libvirt_lxc: missing --name argument for configuration
Segmentation fault
(cherry picked from commit 81efb13b4a33f58c28e0e65dcc9521b983592683)

diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index 6ff2e4643d4a3774e7bca63aebfac2b7ace0848f..2807f3559a86e44595eaacfeb433cf9d33375c0d 100644 (file)
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -1649,7 +1649,8 @@ int main(int argc, char *argv[])
 
 cleanup:
     virPidFileDelete(LXC_STATE_DIR, name);
-    virLXCControllerDeleteInterfaces(ctrl);
+    if (ctrl)
+        virLXCControllerDeleteInterfaces(ctrl);
     for (i = 0 ; i < nttyFDs ; i++)
         VIR_FORCE_CLOSE(ttyFDs[i]);
     VIR_FREE(ttyFDs);