From ecc18608adf7460247fb83431e9b5c82c55c97cf Mon Sep 17 00:00:00 2001
From: tsz8899 <tsz8899@outlook.com>
Date: Sat, 7 Feb 2026 02:37:59 +0800
Subject: [PATCH] [client,windows] Enhance memory safety with NULL checks and
 resource protection

---
 client/Windows/wf_client.c   |  6 ++++++
 client/Windows/wf_gdi.c      | 18 +++++++++++++++++-
 client/Windows/wf_graphics.c | 12 ++++++++----
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/client/Windows/wf_client.c b/client/Windows/wf_client.c
index d6756a31d..ca2acdd87 100644
--- a/client/Windows/wf_client.c
+++ b/client/Windows/wf_client.c
@@ -418,6 +418,12 @@ static BOOL wf_post_connect(freerdp* instance)
 	    wf_image_new(wfc, freerdp_settings_get_uint32(settings, FreeRDP_DesktopWidth),
 	                 freerdp_settings_get_uint32(settings, FreeRDP_DesktopHeight), format, NULL);
 
+	if (!wfc->primary)
+	{
+		WLog_ERR(TAG, "Failed to allocate primary surface");
+		return FALSE;
+	}
+
 	if (!gdi_init_ex(instance, format, 0, wfc->primary->pdata, NULL))
 		return FALSE;
 
diff --git a/client/Windows/wf_gdi.c b/client/Windows/wf_gdi.c
index 4dc964709..ac5f27b92 100644
--- a/client/Windows/wf_gdi.c
+++ b/client/Windows/wf_gdi.c
@@ -118,6 +118,8 @@ static wfBitmap* wf_glyph_new(wfContext* wfc, GLYPH_DATA* glyph)
 {
 	wfBitmap* glyph_bmp;
 	glyph_bmp = wf_image_new(wfc, glyph->cx, glyph->cy, PIXEL_FORMAT_MONO, glyph->aj);
+	if (!glyph_bmp)
+		WLog_ERR(TAG, "wf_image_new failed for glyph");
 	return glyph_bmp;
 }
 
@@ -131,6 +133,11 @@ static BYTE* wf_glyph_convert(wfContext* wfc, int width, int height, const BYTE*
 	const int src_bytes_per_row = (width + 7) / 8;
 	const int dst_bytes_per_row = src_bytes_per_row + (src_bytes_per_row % 2);
 	BYTE* cdata = (BYTE*)malloc(dst_bytes_per_row * height);
+	if (!cdata)
+	{
+		WLog_ERR(TAG, "malloc failed for cdata buffer");
+		return NULL;
+	}
 	const BYTE* src = data;
 
 	for (int indexy = 0; indexy < height; indexy++)
@@ -654,6 +661,7 @@ static BOOL wf_gdi_line_to(rdpContext* context, const LINE_TO_ORDER* line_to)
 
 static BOOL wf_gdi_polyline(rdpContext* context, const POLYLINE_ORDER* polyline)
 {
+	BOOL rc = FALSE;
 	int org_rop2;
 	HPEN hpen;
 	HPEN org_hpen;
@@ -677,6 +685,11 @@ static BOOL wf_gdi_polyline(rdpContext* context, const POLYLINE_ORDER* polyline)
 		int numPoints;
 		numPoints = polyline->numDeltaEntries + 1;
 		pts = (POINT*)malloc(sizeof(POINT) * numPoints);
+		if (!pts)
+		{
+			WLog_ERR(TAG, "malloc failed for polyline points");
+			goto fail;
+		}
 		pts[0].x = temp.x = polyline->xStart;
 		pts[0].y = temp.y = polyline->yStart;
 
@@ -696,10 +709,13 @@ static BOOL wf_gdi_polyline(rdpContext* context, const POLYLINE_ORDER* polyline)
 		free(pts);
 	}
 
+	rc = TRUE;
+
+fail:
 	SelectObject(wfc->drawing->hdc, org_hpen);
 	wf_set_rop2(wfc->drawing->hdc, org_rop2);
 	DeleteObject(hpen);
-	return TRUE;
+	return rc;
 }
 
 static BOOL wf_gdi_memblt(rdpContext* context, MEMBLT_ORDER* memblt)
diff --git a/client/Windows/wf_graphics.c b/client/Windows/wf_graphics.c
index a60054a50..00fac3035 100644
--- a/client/Windows/wf_graphics.c
+++ b/client/Windows/wf_graphics.c
@@ -68,10 +68,14 @@ HBITMAP wf_create_dib(wfContext* wfc, UINT32 width, UINT32 height, UINT32 srcFor
 
 wfBitmap* wf_image_new(wfContext* wfc, UINT32 width, UINT32 height, UINT32 format, const BYTE* data)
 {
-	HDC hdc;
-	wfBitmap* image;
-	hdc = GetDC(NULL);
-	image = (wfBitmap*)malloc(sizeof(wfBitmap));
+	wfBitmap* image = (wfBitmap*)malloc(sizeof(wfBitmap));
+	if (!image)
+	{
+		WLog_ERR(TAG, "malloc failed for wfBitmap");
+		return NULL;
+	}
+
+	HDC hdc = GetDC(NULL);
 	image->hdc = CreateCompatibleDC(hdc);
 	image->bitmap = wf_create_dib(wfc, width, height, format, data, &(image->pdata));
 	image->org_bitmap = (HBITMAP)SelectObject(image->hdc, image->bitmap);