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b=m75WjUhql6v/TjVEVnpOWQ1J/FB300lERpRYAirZ1FL9l76CpCRBfww1t2a35snQD tJHog/nimE0l2EWB/xf3G7qrVi9oDltBkClxF+5wivdARDiJS82n+dVL+gBKvKd8BR v/8JUuiy6YMgm4mnDcTl44gppUgZ/Wyo5IFO+cH2sa9UGBl+NBzQtaPOFGfayVhBD+ 867kDhk1O0Gc6+aNChoD4zHmiq4wxs2CHEGKY/HJnXV/ww0wv+WJhTpq7pcJlFswDD AecDB2oiiUD1yMcLmdGjs44qVENg+pvI5a2EtLzvTW+1c+3RwlEOqTma9hq9YQhjBj MpMRGrTMqp8EQ== Date: Sun, 9 Nov 2025 19:07:04 +0100 From: Alejandro Colomar To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: Alejandro Colomar , Kees Cook , Christopher Bazley , Rasmus Villemoes , Marco Elver , Michal Hocko , Linus Torvalds , Al Viro , Alexander Potapenko , Dmitry Vyukov , Jann Horn , Andrew Morton Subject: [PATCH v3 3/4] kernel: Fix off-by-one benign bugs Message-ID: X-Mailer: git-send-email 2.51.0 References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 16F05C000A X-Stat-Signature: cski4hssmspryei5yfg93s371yjo5rsb X-Rspam-User: X-HE-Tag: 1762711629-423137 X-HE-Meta: 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 QTe4XRTk 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. Cc: Marco Elver Cc: Kees Cook Cc: Christopher Bazley Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Alexander Potapenko Cc: Jann Horn Cc: Andrew Morton Cc: Linus Torvalds Cc: Rasmus Villemoes Cc: Marco Elver Cc: Michal Hocko Cc: Al Viro Signed-off-by: Alejandro Colomar --- kernel/kcsan/kcsan_test.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c index 219d22857c98..8ef8167be745 100644 --- a/kernel/kcsan/kcsan_test.c +++ b/kernel/kcsan/kcsan_test.c @@ -176,7 +176,7 @@ static bool __report_matches(const struct expect_report *r) /* 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 struct expect_report *r) /* 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 "); -- 2.51.0