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Rozycki" Subject: [PATCH v6 2/4] mm: Fix benign off-by-one bugs Message-ID: <9c38dd009c17b0219889c7089d9bdde5aaf28a8e.1765449750.git.alx@kernel.org> 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-Queue-Id: 78946A000E X-Stat-Signature: qni57hefitosnh1duzqds86w37i4zb4u X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1765449840-300970 X-HE-Meta: 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 UY39olx1 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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. Acked-by: 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 Message-ID: <515445ae064d4b8599899bf0d8b480dadd2ff843.1752182685.git.alx@kernel.org> --- mm/kfence/kfence_test.c | 4 ++-- mm/kmsan/kmsan_test.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c index 00034e37bc9f..5725a367246d 100644 --- a/mm/kfence/kfence_test.c +++ b/mm/kfence/kfence_test.c @@ -110,7 +110,7 @@ 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]); switch (r->type) { case KFENCE_ERROR_OOB: cur += scnprintf(cur, end - cur, "BUG: KFENCE: out-of-bounds %s", @@ -140,7 +140,7 @@ static bool report_matches(const struct expect_report *r) /* Access information */ cur = expect[1]; - end = &expect[1][sizeof(expect[1]) - 1]; + end = ARRAY_END(expect[1]); switch (r->type) { case KFENCE_ERROR_OOB: diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c index 902ec48b1e3e..b5ad5dfb2c00 100644 --- a/mm/kmsan/kmsan_test.c +++ b/mm/kmsan/kmsan_test.c @@ -105,7 +105,7 @@ static bool report_matches(const struct expect_report *r) /* Title */ cur = expected_header; - end = &expected_header[sizeof(expected_header) - 1]; + end = ARRAY_END(expected_header); cur += scnprintf(cur, end - cur, "BUG: KMSAN: %s", r->error_type); -- 2.51.0