From 641a07950df3195744c35e0eca3335f949ac2e56 Mon Sep 17 00:00:00 2001
From: morris <maoshengrong@espressif.com>
Date: Mon, 19 Jun 2023 10:38:44 +0800
Subject: [PATCH] vfs_uart: fix out-of-bounds read

when open uart device "/2" on chips only have 2 UART peripherals
---
 components/vfs/vfs_uart.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/components/vfs/vfs_uart.c b/components/vfs/vfs_uart.c
index 74c308f326..52a2622f0f 100644
--- a/components/vfs/vfs_uart.c
+++ b/components/vfs/vfs_uart.c
@@ -106,6 +106,14 @@ static vfs_uart_context_t* s_ctx[UART_NUM] = {
 #endif
 };
 
+static const char *s_uart_mount_points[UART_NUM] = {
+    "/0",
+    "/1",
+#if UART_NUM > 2
+    "/2",
+#endif
+};
+
 #ifdef CONFIG_VFS_SUPPORT_SELECT
 
 typedef struct {
@@ -126,21 +134,21 @@ static esp_err_t uart_end_select(void *end_select_args);
 
 #endif // CONFIG_VFS_SUPPORT_SELECT
 
-static int uart_open(const char * path, int flags, int mode)
+static int uart_open(const char *path, int flags, int mode)
 {
     // this is fairly primitive, we should check if file is opened read only,
     // and error out if write is requested
     int fd = -1;
 
-    if (strcmp(path, "/0") == 0) {
-        fd = 0;
-    } else if (strcmp(path, "/1") == 0) {
-        fd = 1;
-    } else if (strcmp(path, "/2") == 0) {
-        fd = 2;
-    } else {
+    for (int i = 0; i < UART_NUM; i++) {
+        if (strcmp(path, s_uart_mount_points[i]) == 0) {
+            fd = i;
+            break;
+        }
+    }
+    if (fd == -1) {
         errno = ENOENT;
-        return fd;
+        return -1;
     }
 
     s_ctx[fd]->non_blocking = ((flags & O_NONBLOCK) == O_NONBLOCK);