diff --git a/libfreerdp/codec/progressive.c b/libfreerdp/codec/progressive.c
index 6bdd313d8..49be2824c 100644
--- a/libfreerdp/codec/progressive.c
+++ b/libfreerdp/codec/progressive.c
@@ -440,7 +440,7 @@ fail:
 	return NULL;
 }
 
-static BOOL progressive_allocate_tile_cache(PROGRESSIVE_SURFACE_CONTEXT* surface)
+static BOOL progressive_allocate_tile_cache(PROGRESSIVE_SURFACE_CONTEXT* surface, size_t min)
 {
 	size_t x;
 	size_t oldIndex = 0;
@@ -451,7 +451,8 @@ static BOOL progressive_allocate_tile_cache(PROGRESSIVE_SURFACE_CONTEXT* surface
 	if (surface->tiles)
 	{
 		oldIndex = surface->gridSize;
-		surface->gridSize += 1024;
+		while (surface->gridSize < min)
+			surface->gridSize += 1024;
 	}
 
 	void* tmp = winpr_aligned_recalloc(surface->tiles, surface->gridSize,
@@ -481,7 +482,6 @@ static BOOL progressive_allocate_tile_cache(PROGRESSIVE_SURFACE_CONTEXT* surface
 static PROGRESSIVE_SURFACE_CONTEXT* progressive_surface_context_new(UINT16 surfaceId, UINT32 width,
                                                                     UINT32 height)
 {
-	UINT32 x;
 	PROGRESSIVE_SURFACE_CONTEXT* surface = (PROGRESSIVE_SURFACE_CONTEXT*)winpr_aligned_calloc(
 	    1, sizeof(PROGRESSIVE_SURFACE_CONTEXT), 32);
 
@@ -495,7 +495,7 @@ static PROGRESSIVE_SURFACE_CONTEXT* progressive_surface_context_new(UINT16 surfa
 	surface->gridHeight = (height + (64 - height % 64)) / 64;
 	surface->gridSize = surface->gridWidth * surface->gridHeight;
 
-	if (!progressive_allocate_tile_cache(surface))
+	if (!progressive_allocate_tile_cache(surface, surface->gridSize))
 	{
 		progressive_surface_context_free(surface);
 		return NULL;
@@ -571,7 +571,7 @@ static BOOL progressive_surface_tile_replace(PROGRESSIVE_SURFACE_CONTEXT* surfac
 	}
 	if (surface->numUpdatedTiles >= surface->tilesSize)
 	{
-		if (!progressive_allocate_tile_cache(surface))
+		if (!progressive_allocate_tile_cache(surface, surface->numUpdatedTiles))
 			return FALSE;
 	}
 
@@ -2495,11 +2495,8 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
                              UINT32 frameId)
 {
 	INT32 rc = 1;
-	UINT32 i;
-	wStream *s, ss;
-	size_t start, end;
-	REGION16 clippingRects, updateRegion;
-	PROGRESSIVE_BLOCK_REGION* region = &progressive->region;
+
+	WINPR_ASSERT(progressive);
 	PROGRESSIVE_SURFACE_CONTEXT* surface = progressive_get_surface_data(progressive, surfaceId);
 
 	if (!surface)
@@ -2509,13 +2506,18 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
 		return -1001;
 	}
 
+	PROGRESSIVE_BLOCK_REGION* region = &progressive->region;
+	WINPR_ASSERT(region);
+
 	if (surface->frameId != frameId)
 	{
 		surface->frameId = frameId;
 		surface->numUpdatedTiles = 0;
 	}
 
-	s = Stream_StaticConstInit(&ss, pSrcData, SrcSize);
+	wStream ss = { 0 };
+	wStream* s = Stream_StaticConstInit(&ss, pSrcData, SrcSize);
+	WINPR_ASSERT(s);
 
 	switch (DstFormat)
 	{
@@ -2530,7 +2532,7 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
 			break;
 	}
 
-	start = Stream_GetPosition(s);
+	const size_t start = Stream_GetPosition(s);
 	progressive->state = 0; /* Set state to not initialized */
 	while (Stream_GetRemainingLength(s) > 0)
 	{
@@ -2538,7 +2540,7 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
 			goto fail;
 	}
 
-	end = Stream_GetPosition(s);
+	const size_t end = Stream_GetPosition(s);
 	if ((end - start) != SrcSize)
 	{
 		WLog_Print(progressive->log, WLOG_ERROR,
@@ -2548,12 +2550,14 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
 		goto fail;
 	}
 
+	REGION16 clippingRects = { 0 };
 	region16_init(&clippingRects);
 
-	for (i = 0; i < region->numRects; i++)
+	for (UINT32 i = 0; i < region->numRects; i++)
 	{
-		RECTANGLE_16 clippingRect;
+		RECTANGLE_16 clippingRect = { 0 };
 		const RFX_RECT* rect = &(region->rects[i]);
+
 		clippingRect.left = (UINT16)nXDst + rect->x;
 		clippingRect.top = (UINT16)nYDst + rect->y;
 		clippingRect.right = clippingRect.left + rect->width;
@@ -2561,22 +2565,30 @@ INT32 progressive_decompress(PROGRESSIVE_CONTEXT* progressive, const BYTE* pSrcD
 		region16_union_rect(&clippingRects, &clippingRects, &clippingRect);
 	}
 
-	for (i = 0; i < surface->numUpdatedTiles; i++)
+	for (UINT32 i = 0; i < surface->numUpdatedTiles; i++)
 	{
-		UINT32 nbUpdateRects, j;
-		const RECTANGLE_16* updateRects;
-		RECTANGLE_16 updateRect;
-		RFX_PROGRESSIVE_TILE* tile = surface->tiles[surface->updatedTileIndices[i]];
+		UINT32 nbUpdateRects = 0;
+		const RECTANGLE_16* updateRects = NULL;
+		RECTANGLE_16 updateRect = { 0 };
+
+		WINPR_ASSERT(surface->updatedTileIndices);
+		const UINT32 index = surface->updatedTileIndices[i];
+
+		WINPR_ASSERT(index < surface->tilesSize);
+		RFX_PROGRESSIVE_TILE* tile = surface->tiles[index];
+		WINPR_ASSERT(tile);
 
 		updateRect.left = nXDst + tile->x;
 		updateRect.top = nYDst + tile->y;
 		updateRect.right = updateRect.left + 64;
 		updateRect.bottom = updateRect.top + 64;
+
+		REGION16 updateRegion = { 0 };
 		region16_init(&updateRegion);
 		region16_intersect_rect(&updateRegion, &clippingRects, &updateRect);
 		updateRects = region16_rects(&updateRegion, &nbUpdateRects);
 
-		for (j = 0; j < nbUpdateRects; j++)
+		for (UINT32 j = 0; j < nbUpdateRects; j++)
 		{
 			const RECTANGLE_16* rect = &updateRects[j];
 			const UINT32 nXSrc = rect->left - (nXDst + tile->x);