From: David Howells <dhowells@redhat.com>
Date: Thu, 25 Jun 2026 14:06:24 +0000 (+0100)
Subject: iov_iter: Fix missing alloc fail check in iov_iter_extract_bvec_pages()
X-Git-Tag: v7.2-rc2~14^2~3^2~9
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=70531f4f3a143f81baf549da7f59a24a9f87a65c;p=thirdparty%2Flinux.git

iov_iter: Fix missing alloc fail check in iov_iter_extract_bvec_pages()

Fix iov_iter_extract_bvec_pages() to check if want_pages_array() fails and,
if so, return -ENOMEM appropriately.

Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/20260625140640.3116900-7-dhowells@redhat.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
cc: Ming Lei <ming.lei@redhat.com>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: Christoph Hellwig <hch@infradead.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 0f320b4e82a8..3dfad70328eb 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1637,6 +1637,8 @@ static ssize_t iov_iter_extract_bvec_pages(struct iov_iter *i,
 	bi.bi_bvec_done = skip;
 
 	maxpages = want_pages_array(pages, maxsize, skip, maxpages);
+	if (!maxpages)
+		return -ENOMEM;
 
 	while (bi.bi_size && bi.bi_idx < i->nr_segs) {
 		struct bio_vec bv = bvec_iter_bvec(i->bvec, bi);