From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 81D182FA0C6; Sat, 19 Sep 2026 00:27:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789777642; cv=none; b=QY6Eq8z24s5XP5EZL7mEdpmkOGOUHWJWoXl9rfGlu2bSmS8kTSSglyYRSmLasRN8wvZqYAjruK/m20kXeT/E32AUNioJfxQNvQLNwbxS7jbdVwgf28dte0xd6FWuN5lfx2GR304rYRwE5Qy7KrbEPC11w60WtU5SRyZJp7srl2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789777642; c=relaxed/simple; bh=RrnZl1rRNO0P6CbEXl0y0T0bYtGLvcfjTXHiHq9pwKE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=PQ7qddQHNhwxvFjEpFaxYdIai3uhbUyI6mQutajI8544aZuzomMAS++7vBhHPuzFCGW+Efyf1MQuRsh6pPGYi9SSOGE4+pbyJPZrh8oHO+S7zBH0inlOsmK1i1vWL12JV+41EGwlMvwejBJKLFFg870AOEcAm1cxD7vKdbc+W3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BIFLOLJ+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BIFLOLJ+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE97C1F008A1; Sat, 19 Sep 2026 00:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789777634; bh=h9mGH20M5Bjep7ay96qxR5rLVMrKdFFEuXs8xVeKA0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BIFLOLJ+yGbuUWH1j4NGjLCY2l4Pz8cVfBn0MdZxF+zvbhZdbnFgogJc3KvZ8IZ4o giuMAP8Q/7YZzrPkPt1jb4Nxheu/pEZYrJVZz0S9y35tOOwQKZzNszduVG9JHL/ZbD S+fQvza+CY8yMKVpbpuJ5xsiAKzzqmUqtvhuY6WJj+pJUmrubbPnn7AYpy++v/yl4p vG95NPKsZdNLCWPNXiLN3MUw/5CFXP4vFOiDMZUZrT1XWwoFbjDIarP1ABR5Kqd7+w qZaIOs0rUI/p1th2D8Rxe/2P0TnG5dOJEIFZJfqgkz+6KpdzgnfAwjTr/CvdbqxINW q7aiCoPx7N+Fw== From: Kees Cook To: Bill Wendling Cc: Kees Cook , Andy Shevchenko , Dave Jiang , nvdimm@lists.linux.dev, Alison Schofield , Greg Kroah-Hartman , Guangshuo Li , Ira Weiny , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Vishal Verma , Steven Rostedt , nikitash.mariiaw@gmail.com, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v2 8/9] nvdimm: ndtest: Return the string length from flags_show() Date: Fri, 18 Sep 2026 17:27:06 -0700 Message-Id: <20260919002714.4060307-8-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260919002658.stay.929-kees@kernel.org> References: <20260919002658.stay.929-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Developer-Signature: v=1; a=openpgp-sha256; l=1505; i=kees@kernel.org; h=from:subject; bh=RrnZl1rRNO0P6CbEXl0y0T0bYtGLvcfjTXHiHq9pwKE=; b=owGbwMvMwCVmps19z/KJym7G02pJDFlrr93KXqEn1Scf3tN1J8qguX3iuqhfybvu/TJ3faBQu rswJa+io5SFQYyLQVZMkSXIzj3OxeNte7j7XEWYOaxMIEMYuDgFYCJJXAx/JSPvPpr8z/dhRISm nK2z4JV7etIPNzKbmBm8ytlX+XeJJMP/9Hofiemy+dYde5UONVl0C/AW67kvTp7tOOHY+g1M1kd 4AA== X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit flags_show() build their output with a seq_buf and return seq_buf_used(), which may include the trailing NUL byte when the seq_buf has overflowed. Use seq_buf_strlen() instead. The flag names are far shorter than the PAGE_SIZE buffer sysfs provides, so this cannot overflow today. Build tested ARCH=x86_64 with GCC 16.2.0, built out of tree with make M=tools/testing/nvdimm: tools/testing/nvdimm/test/ndtest.o Assisted-by: LLM Reviewed-by: Andy Shevchenko Reviewed-by: Dave Jiang Signed-off-by: Kees Cook --- Cc: Cc: Alison Schofield Cc: Dave Jiang Cc: Greg Kroah-Hartman Cc: Guangshuo Li Cc: Ira Weiny Cc: Uwe Kleine-König Cc: Vishal Verma --- tools/testing/nvdimm/test/ndtest.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/nvdimm/test/ndtest.c b/tools/testing/nvdimm/test/ndtest.c index 2051ad5d4882..f097f2992966 100644 --- a/tools/testing/nvdimm/test/ndtest.c +++ b/tools/testing/nvdimm/test/ndtest.c @@ -693,7 +693,7 @@ static ssize_t flags_show(struct device *dev, if (seq_buf_used(&s)) seq_buf_printf(&s, "\n"); - return seq_buf_used(&s); + return seq_buf_strlen(&s); } static DEVICE_ATTR_RO(flags); -- 2.34.1