From c0d068229be72078ab75890939d2c1c3ee1ad9f2 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Tue, 6 May 2025 17:43:49 +0200
Subject: [PATCH] xfree86: common: extra safety checks for NULL pointers

Even though it's unlikely ever getting it, still safer to have some
extra checks / asserts than unexpected segfault.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 hw/xfree86/common/xf86Configure.c | 16 ++++++++--------
 hw/xfree86/common/xf86Events.c    |  2 +-
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/hw/xfree86/common/xf86Configure.c b/hw/xfree86/common/xf86Configure.c
index b1fc83b14..6242cad50 100644
--- a/hw/xfree86/common/xf86Configure.c
+++ b/hw/xfree86/common/xf86Configure.c
@@ -341,9 +341,8 @@ configureLayoutSection(void)
     ptr->lay_identifier = "X.org Configured";
 
     {
-        XF86ConfInputrefPtr iptr;
-
-        iptr = malloc(sizeof(XF86ConfInputrefRec));
+        XF86ConfInputrefPtr iptr = calloc(1, sizeof(XF86ConfInputrefRec));
+        assert(iptr);
         iptr->list.next = NULL;
         iptr->iref_option_lst = NULL;
         iptr->iref_inputdev_str = XNFstrdup("Mouse0");
@@ -355,9 +354,8 @@ configureLayoutSection(void)
     }
 
     {
-        XF86ConfInputrefPtr iptr;
-
-        iptr = malloc(sizeof(XF86ConfInputrefRec));
+        XF86ConfInputrefPtr iptr = calloc(1, sizeof(XF86ConfInputrefRec));
+        assert(iptr);
         iptr->list.next = NULL;
         iptr->iref_option_lst = NULL;
         iptr->iref_inputdev_str = XNFstrdup("Keyboard0");
@@ -369,10 +367,10 @@ configureLayoutSection(void)
     }
 
     for (scrnum = 0; scrnum < nDevToConfig; scrnum++) {
-        XF86ConfAdjacencyPtr aptr;
         char *tmp;
 
-        aptr = malloc(sizeof(XF86ConfAdjacencyRec));
+        XF86ConfAdjacencyPtr aptr = calloc(1, sizeof(XF86ConfAdjacencyRec));
+        assert(aptr);
         aptr->list.next = NULL;
         aptr->adj_x = 0;
         aptr->adj_y = 0;
@@ -466,6 +464,7 @@ handle_detailed_input(struct detailed_monitor_section *det_mon, void *data)
         ptr->mon_modelname = realloc(ptr->mon_modelname,
                                      strlen((char *) (det_mon->section.name)) +
                                      1);
+        assert(ptr->mon_modelname);
         strcpy(ptr->mon_modelname, (char *) (det_mon->section.name));
         break;
     case DS_RANGES:
@@ -655,6 +654,7 @@ DoConfigure(void)
         XF86ConfMonitorPtr monitor_ptr;
         XF86ConfScreenPtr screen_ptr;
 
+        assert(xf86config);
         device_ptr = configureDeviceSection(screennum);
         xf86config->conf_device_lst = (XF86ConfDevicePtr) xf86addListItem((glp)
                                                                           xf86config->
diff --git a/hw/xfree86/common/xf86Events.c b/hw/xfree86/common/xf86Events.c
index 9583fce21..08c5a6127 100644
--- a/hw/xfree86/common/xf86Events.c
+++ b/hw/xfree86/common/xf86Events.c
@@ -616,7 +616,7 @@ removeInputHandler(IHPtr ih)
         p = InputHandlers;
         while (p && p->next != ih)
             p = p->next;
-        if (ih)
+        if (ih && p)
             p->next = ih->next;
     }
     free(ih);