From 06c7ef7f6a8898588e81d71ce39f2860fac174a4 Mon Sep 17 00:00:00 2001
From: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Date: Thu, 18 Jul 2019 07:31:42 -0400
Subject: [PATCH] lib/ftl: check for io not being NULL before dereferencing

ftl_io_free() handles NULL io being passed, but shouldn't
dereference it before returning.

Change-Id: Ia705d4ab9f8b3569e9704a1f97e70f7579084efb
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/462487
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Wojciech Malikowski <wojciech.malikowski@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
---
 lib/ftl/ftl_io.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/ftl/ftl_io.c b/lib/ftl/ftl_io.c
index 119f3dfcb..398e195c0 100644
--- a/lib/ftl/ftl_io.c
+++ b/lib/ftl/ftl_io.c
@@ -570,12 +570,13 @@ ftl_io_reset(struct ftl_io *io)
 void
 ftl_io_free(struct ftl_io *io)
 {
-	struct ftl_io *parent = io->parent;
+	struct ftl_io *parent;
 
 	if (!io) {
 		return;
 	}
 
+	parent = io->parent;
 	if (parent && ftl_io_remove_child(io)) {
 		ftl_io_complete(parent);
 	}