From nobody Mon Feb 9 19:25:56 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EC5113793BD; Thu, 29 Jan 2026 07:02:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769670161; cv=none; b=G+A2ucg0nOhbKnYTP7emJv5A8iPBGoVLrbzGj1YQym0e2X9lYypSAZLP8vICVvc/vGH5auaDAFcQeVRsfmPzxP182iiTRXDAwkiBX7N6RkXf7VVB0S191oCwOwh3DpMYY1nCfCFkWO/O/GNppFlcreLjl1UIyMF/q2nO1SWzi0U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769670161; c=relaxed/simple; bh=ssSPpNgcEIU6jl4Sq+EPUHHZsZ77Yz+4TBW+QrALebs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=oEFphcl8LEBlNPryWra6J3o173US78x2MSi5fIqlJTP16qnm6NFSqxDs8f9DaI2RGTkWDoryGF16sVOuUN1230URt9/X8GMnJxL6eToWr66Q2Nd5ZBy2IPU3bLQae/ueAeisTCTfO/NftsUcTXDLkRSk+/j1s9t7TcGwKXtJgoc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: 7c19514efce011f0b0f03b4cfa9209d1-20260129 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.6,REQID:2da66a11-4624-4e65-8b53-3d04f8750ff3,IP:0,UR L:0,TC:0,Content:-5,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:-5 X-CID-META: VersionHash:a9d874c,CLOUDID:896c6413a4af6cd7e7bef1d14da6ef38,BulkI D:nil,BulkQuantity:0,Recheck:0,SF:81|82|102|850|898,TC:nil,Content:0|15|50 ,EDM:-3,IP:nil,URL:0,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,O SA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 7c19514efce011f0b0f03b4cfa9209d1-20260129 X-User: jiangfeng@kylinos.cn Received: from localhost.localdomain [(10.44.16.150)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 1062922104; Thu, 29 Jan 2026 15:02:33 +0800 From: Feng Jiang To: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, akpm@linux-foundation.org, kees@kernel.org, andy@kernel.org, jiangfeng@kylinos.cn, ebiggers@kernel.org, martin.petersen@oracle.com, herbert@gondor.apana.org.au, samuel.holland@sifive.com, ajones@ventanamicro.com, charlie@rivosinc.com, conor.dooley@microchip.com, linus.walleij@linaro.org, nathan@kernel.org Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v6 2/8] lib/string_kunit: add correctness test for strnlen() Date: Thu, 29 Jan 2026 15:02:21 +0800 Message-Id: <20260129070227.220866-3-jiangfeng@kylinos.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260129070227.220866-1-jiangfeng@kylinos.cn> References: <20260129070227.220866-1-jiangfeng@kylinos.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a KUnit test for strnlen() to verify correctness across different string lengths and memory alignments. Use vmalloc() to place the NUL character at the page boundary to ensure over-reads are detected. Suggested-by: Andy Shevchenko Suggested-by: Kees Cook Signed-off-by: Feng Jiang --- lib/tests/string_kunit.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index 335f2e6c2ed6..886d21d32fa9 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -132,6 +132,40 @@ static void string_test_strlen(struct kunit *test) vfree(buf); } =20 +static void string_test_strnlen(struct kunit *test) +{ + size_t buf_size; + char *buf, *s; + + buf_size =3D PAGE_ALIGN(STRING_TEST_MAX_LEN + STRING_TEST_MAX_OFFSET + 1); + buf =3D vmalloc(buf_size); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf); + + memset(buf, 'A', buf_size); + + for (size_t offset =3D 0; offset < STRING_TEST_MAX_OFFSET; offset++) { + for (size_t len =3D 0; len <=3D STRING_TEST_MAX_LEN; len++) { + s =3D buf + buf_size - 1 - offset - len; + s[len] =3D '\0'; + + if (len > 0) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 1), len - 1); + if (len > 1) + KUNIT_EXPECT_EQ(test, strnlen(s, len - 2), len - 2); + + KUNIT_EXPECT_EQ(test, strnlen(s, len), len); + + KUNIT_EXPECT_EQ(test, strnlen(s, len + 1), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 2), len); + KUNIT_EXPECT_EQ(test, strnlen(s, len + 10), len); + + s[len] =3D 'A'; + } + } + + vfree(buf); +} + static void string_test_strchr(struct kunit *test) { const char *test_string =3D "abcdefghijkl"; @@ -647,6 +681,7 @@ static struct kunit_case string_test_cases[] =3D { KUNIT_CASE(string_test_memset32), KUNIT_CASE(string_test_memset64), KUNIT_CASE(string_test_strlen), + KUNIT_CASE(string_test_strnlen), KUNIT_CASE(string_test_strchr), KUNIT_CASE(string_test_strnchr), KUNIT_CASE(string_test_strspn), --=20 2.25.1