+ kernel-fix-off-by-one-benign-bugs.patch added to mm-nonmm-unstable branch

+ kernel-fix-off-by-one-benign-bugs.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: kernel: fix off-by-one benign bugs
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     kernel-fix-off-by-one-benign-bugs.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kernel-fix-off-by-one-benign-bugs.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: Alejandro Colomar <alx@kernel.org>
Subject: kernel: fix off-by-one benign bugs
Date: Thu, 11 Dec 2025 11:44:00 +0100

We were wasting a byte due to an off-by-one bug.  s[c]nprintf() doesn't
write more than $2 bytes including the null byte, so trying to pass
'size-1' there is wasting one byte.

This is essentially the same as the previous commit, in a different
file.

Link: https://lkml.kernel.org/r/b4a945a4d40b7104364244f616eb9fb9f1fa691f.1765449750.git.alx@kernel.org
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Christopher Bazley <chris.bazley.wg14@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/kcsan/kcsan_test.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/kcsan/kcsan_test.c~kernel-fix-off-by-one-benign-bugs
+++ a/kernel/kcsan/kcsan_test.c
@@ -176,7 +176,7 @@ static bool __report_matches(const struc
 
 	/* Title */
 	cur = expect[0];
-	end = &expect[0][sizeof(expect[0]) - 1];
+	end = ARRAY_END(expect[0]);
 	cur += scnprintf(cur, end - cur, "BUG: KCSAN: %s in ",
 			 is_assert ? "assert: race" : "data-race");
 	if (r->access[1].fn) {
@@ -200,7 +200,7 @@ static bool __report_matches(const struc
 
 	/* Access 1 */
 	cur = expect[1];
-	end = &expect[1][sizeof(expect[1]) - 1];
+	end = ARRAY_END(expect[1]);
 	if (!r->access[1].fn)
 		cur += scnprintf(cur, end - cur, "race at unknown origin, with ");
 
_

Patches currently in -mm which might be from alx@kernel.org are

array_sizeh-add-array_end.patch
mm-fix-benign-off-by-one-bugs.patch
kernel-fix-off-by-one-benign-bugs.patch
mm-use-array_end-instead-of-open-coding-it.patch