+ lib-fix-length-calculation-in-extract_kvec_to_sg.patch added to mm-nonmm-unstable branch

+ lib-fix-length-calculation-in-extract_kvec_to_sg.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: lib: fix length calculation in extract_kvec_to_sg
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     lib-fix-length-calculation-in-extract_kvec_to_sg.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-fix-length-calculation-in-extract_kvec_to_sg.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Christian A. Ehrhardt" <lk@c--e.de>
Subject: lib: fix length calculation in extract_kvec_to_sg
Date: Mon, 23 Mar 2026 22:23:50 +0100

When extracting from a kvec to a scatterlist, do not cross page
boundaries.  The required length is already calculated but not used as
intended.

The previous changes to the kunit_iov_iter.c demonstrate that the patch is
necessary.

Link: https://lkml.kernel.org/r/20260323212350.807118-4-lk@c--e.de
Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist")
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Reviewed-by: Josh Law <objecting@objecting.org>
Tested-by: Josh Law <objecting@objecting.org>
Cc: David Howells <dhowells@redhat.com>
Cc: David Gow <davidgow@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/scatterlist.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/lib/scatterlist.c~lib-fix-length-calculation-in-extract_kvec_to_sg
+++ a/lib/scatterlist.c
@@ -1247,7 +1247,7 @@ static ssize_t extract_kvec_to_sg(struct
 			else
 				page = virt_to_page((void *)kaddr);
 
-			sg_set_page(sg, page, len, off);
+			sg_set_page(sg, page, seg, off);
 			sgtable->nents++;
 			sg++;
 			sg_max--;
_

Patches currently in -mm which might be from lk@c--e.de are

lib-kunit_iov_iter-improve-error-detection.patch
lib-kunit_iov_iter-add-tests-for-extract_iter_to_sg.patch
lib-fix-length-calculation-in-extract_kvec_to_sg.patch