From 496a51b37143c690a06612a6bd58827ef2341761 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Thu, 31 Oct 2024 19:02:24 +0800
Subject: [PATCH] lib/iov_iter.c: initialize bi.bi_idx before iterating over
 bvec

Initialize bi.bi_idx as 0 before iterating over bvec, otherwise
garbage data can be used as ->bi_idx.

Cc: Christoph Hellwig <hch@lst.de>
Reported-and-tested-by: Klara Modin <klarasmodin@gmail.com>
Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 lib/iov_iter.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9fc06f5fb748..c761f6db3cb4 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1699,6 +1699,7 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i,
 		i->bvec++;
 		skip = 0;
 	}
+	bi.bi_idx = 0;
 	bi.bi_size = maxsize + skip;
 	bi.bi_bvec_done = skip;
 
-- 
2.25.1