From: Jerome Forissier <jerome.forissier@linaro.org>
Date: Thu, 17 Apr 2025 13:26:59 +0000 (+0200)
Subject: net-lwip: wget: add LMB and buffer checks
X-Git-Tag: v2025.07-rc3~10^2~2
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e40c910e88a9a38ee1335ab1391dc2ee83993a65;p=pandora-u-boot.git

net-lwip: wget: add LMB and buffer checks

Legacy NET wget invokes a store_block() function which performs buffer
validation (LMB, address wrapping). Do the same with NET_LWIP.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Suggested-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Acked-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Tested-by: Sughosh Ganu <sughosh.ganu@linaro.org>
---

diff --git a/net/lwip/wget.c b/net/lwip/wget.c
index 812b3c3e8e6..ea1113e18b1 100644
--- a/net/lwip/wget.c
+++ b/net/lwip/wget.c
@@ -6,6 +6,7 @@
 #include <display_options.h>
 #include <efi_loader.h>
 #include <image.h>
+#include <linux/kconfig.h>
 #include <lwip/apps/http_client.h>
 #include "lwip/altcp_tls.h"
 #include <lwip/errno.h>
@@ -202,11 +203,58 @@ static int parse_legacy_arg(char *arg, char *nurl, size_t rem)
 	return 0;
 }
 
+/**
+ * store_block() - copy received data
+ *
+ * This function is called by the receive callback to copy a block of data
+ * into its final location (ctx->daddr). Before doing so, it checks if the copy
+ * is allowed.
+ *
+ * @ctx: the context for the current transfer
+ * @src: the data received from the TCP stack
+ * @len: the length of the data
+ */
+static int store_block(struct wget_ctx *ctx, void *src, u16_t len)
+{
+	ulong store_addr = ctx->daddr;
+	uchar *ptr;
+
+	/* Avoid overflow */
+	if (wget_info->buffer_size && wget_info->buffer_size < ctx->size + len)
+		return -1;
+
+	if (CONFIG_IS_ENABLED(LMB) && wget_info->set_bootdev) {
+		if (store_addr + len < store_addr ||
+		    lmb_read_check(store_addr, len)) {
+			if (!wget_info->silent) {
+				printf("\nwget error: ");
+				printf("trying to overwrite reserved memory\n");
+			}
+			return -1;
+		}
+	}
+
+	ptr = map_sysmem(store_addr, len);
+	memcpy(ptr, src, len);
+	unmap_sysmem(ptr);
+
+	ctx->daddr += len;
+	ctx->size += len;
+	if (ctx->size - ctx->prevsize > PROGRESS_PRINT_STEP_BYTES) {
+		if (!wget_info->silent)
+			printf("#");
+		ctx->prevsize = ctx->size;
+	}
+
+	return 0;
+}
+
 static err_t httpc_recv_cb(void *arg, struct altcp_pcb *pcb, struct pbuf *pbuf,
 			   err_t err)
 {
 	struct wget_ctx *ctx = arg;
 	struct pbuf *buf;
+	err_t ret;
 
 	if (!pbuf)
 		return ERR_BUF;
@@ -215,19 +263,17 @@ static err_t httpc_recv_cb(void *arg, struct altcp_pcb *pcb, struct pbuf *pbuf,
 		ctx->start_time = get_timer(0);
 
 	for (buf = pbuf; buf; buf = buf->next) {
-		memcpy((void *)ctx->daddr, buf->payload, buf->len);
-		ctx->daddr += buf->len;
-		ctx->size += buf->len;
-		if (!wget_info->silent &&
-		    ctx->size - ctx->prevsize > PROGRESS_PRINT_STEP_BYTES) {
-			printf("#");
-			ctx->prevsize = ctx->size;
+		if (store_block(ctx, buf->payload, buf->len) < 0) {
+			altcp_abort(pcb);
+			ret = ERR_BUF;
+			goto out;
 		}
 	}
-
 	altcp_recved(pcb, pbuf->tot_len);
+	ret = ERR_OK;
+out:
 	pbuf_free(pbuf);
-	return ERR_OK;
+	return ret;
 }
 
 static void httpc_result_cb(void *arg, httpc_result_t httpc_result,