From b898977fd823c4ef4479c46b397f6ad403d9dc73 Mon Sep 17 00:00:00 2001
From: xujunjun <xujunjun@landicorp.com>
Date: Tue, 11 Jan 2022 15:10:45 +0800
Subject: [PATCH] Set the limit, the cursor cannot be set to a negative number

---
 lfs.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/lfs.c b/lfs.c
index d976389..9917dbf 100644
--- a/lfs.c
+++ b/lfs.c
@@ -3066,9 +3066,18 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
     if (whence == LFS_SEEK_SET) {
         npos = off;
     } else if (whence == LFS_SEEK_CUR) {
-        npos = file->pos + off;
+        if ((lfs_soff_t)file->pos + off < 0) {
+            return LFS_ERR_INVAL;
+        } else {
+            npos = file->pos + off;
+        }
     } else if (whence == LFS_SEEK_END) {
-        npos = lfs_file_rawsize(lfs, file) + off;
+        lfs_soff_t res = lfs_file_rawsize(lfs, file) + off;
+        if (res < 0) {
+            return LFS_ERR_INVAL;
+        } else {
+            npos = res;
+        }
     }
 
     if (npos > lfs->file_max) {