diff --git a/src/ipc/ipc3/helper.c b/src/ipc/ipc3/helper.c
index 4d87f042dd1d..37d00b9eb912 100644
--- a/src/ipc/ipc3/helper.c
+++ b/src/ipc/ipc3/helper.c
@@ -302,7 +302,11 @@ static int comp_specific_builder(struct sof_ipc_comp *comp,
 		if (IPC_TAIL_IS_SIZE_INVALID(*proc))
 			return -EBADMSG;
 
-		if (proc->comp.hdr.size + proc->size > SOF_IPC_MSG_MAX_SIZE)
+		/* compare without adding the two host-supplied uint32_t values,
+		 * which could wrap and let an oversized proc->size pass
+		 */
+		if (proc->comp.hdr.size > SOF_IPC_MSG_MAX_SIZE ||
+		    proc->size > SOF_IPC_MSG_MAX_SIZE - proc->comp.hdr.size)
 			return -EBADMSG;
 
 		config->process.type = proc->type;
diff --git a/src/ipc/ipc3/host-page-table.c b/src/ipc/ipc3/host-page-table.c
index e90203a79dce..dbd0fd0fe030 100644
--- a/src/ipc/ipc3/host-page-table.c
+++ b/src/ipc/ipc3/host-page-table.c
@@ -16,6 +16,25 @@
 
 LOG_MODULE_DECLARE(ipc, CONFIG_SOF_LOG_LEVEL);
 
+/*
+ * Size in bytes of the DSP-side buffer that receives the compressed host page
+ * table. DSP targets define PLATFORM_PAGE_TABLE_SIZE; the host/library builds
+ * (e.g. testbench, fuzzer) allocate it as HOST_PAGE_SIZE in drivers/host/ipc.c
+ * and do not define PLATFORM_PAGE_TABLE_SIZE, so fall back to that.
+ */
+#ifndef PLATFORM_PAGE_TABLE_SIZE
+#define PLATFORM_PAGE_TABLE_SIZE HOST_PAGE_SIZE
+#endif
+
+/*
+ * The compressed page table stores one 20-bit entry per host page, so the
+ * number of pages whose entries fit in the page table buffer is
+ * (buffer bytes * 8 bits/byte) / 20 bits/page.
+ */
+#define HOST_PAGE_TABLE_BITS_PER_PAGE	20
+#define HOST_PAGE_TABLE_MAX_PAGES \
+	(PLATFORM_PAGE_TABLE_SIZE * 8 / HOST_PAGE_TABLE_BITS_PER_PAGE)
+
 /*
  * Parse the host page tables and create the audio DMA SG configuration
  * for host audio DMA buffer. This involves creating a dma_sg_elem for each
@@ -216,6 +235,19 @@ int ipc_process_host_buffer(struct ipc *ipc,
 	struct ipc_data_host_buffer *data_host_buffer;
 	int err;
 
+	/*
+	 * The host-supplied page count is used both to size DSP-side
+	 * allocations and to compute the DMA transfer length for the
+	 * compressed page table. Reject a count that would not fit in the
+	 * page table buffer before doing any arithmetic that could overflow
+	 * (ring->pages * 20). pages == 0 is also invalid and would underflow
+	 * the ring->size sanity check in ipc_parse_page_descriptors().
+	 */
+	if (ring->pages == 0 || ring->pages > HOST_PAGE_TABLE_MAX_PAGES) {
+		tr_err(&ipc_tr, "ipc: invalid page count %u", ring->pages);
+		return -EINVAL;
+	}
+
 	data_host_buffer = ipc_platform_get_host_buffer(ipc);
 	dma_sg_init(elem_array);