1 files changed, 3 insertions, 1 deletions
diff --git a/fs/fs.c b/fs/fs.c
index 440adae14c..966abe9408 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -935,8 +935,10 @@ int erase(int fd, loff_t count, loff_t offset)
 	f = &files[fd];
 	if (offset >= f->size)
 		return 0;
-	if (count > f->size - offset)
+	if (count == ERASE_SIZE_ALL || count > f->size - offset)
 		count = f->size - offset;
+	if (count < 0)
+		return -EINVAL;
 
 	fsdrv = f->fsdev->driver;
 	if (fsdrv->erase)