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 E278D4D1788; Wed, 30 Sep 2026 23:52:53 +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=1790812375; cv=none; b=l1IDRL90alPzokG4diX1FRZIuCEZhM0ckmS/h4m9QcfgXxyQRPtE+Wv9UCoD5r96ghbR6B4kVhEVAVTTZZ2xn4ChKUg0kQYEBxqiuV20ZzHdrX4gAIT7xYQ/nVly4Rzrx66bL4lZAtuhBxgIObryH1AtFnbIpgIbEL7bUIVMc6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790812375; c=relaxed/simple; bh=2AtxDeGumxoxvmY3xbTN0AxqV9yj2Kg5m9bB3ZVwy3c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=h1hRJ6t0mPALt1oTkVkSom+7n+zVoGmuniLXXVvkMrdetEB/wXHMidmvZ5z5wP9TFIJzAqk9gjgl0VmbboKPbq07KHQNZerIqboErLni56BjsYs/azsGuLA8wGvzuCA+26MxZBXaAl8FPbJiQ2oArvdoceL1IYIX0dtXAj2faXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oUlsyo40; 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="oUlsyo40" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28E631F008A2; Wed, 30 Sep 2026 23:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790812371; bh=gG1wlNEkwzjCuDccxFHfdxljPSEWGUnfDlpru3ASekE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oUlsyo4092+ef0k+W+EK149GNGIaA9duEa6FaHmoSpE5O4ArtyyKJt8dYAhqtclfG 7U0LVYd9laCr0WOTnhaZycuAlk5f5/piWQbjaXzQeZ25M9QJojYIwpaVk+825RAgw5 CGZUHg0tboENUnLo9eZohwgChOfvgafiC3wayHH5k11wTs0BpZjBKHIgxPBthM7lIl yIq0RWDJtIcEQN4tpoTsZ92RL6pQNbKqLVYCawCUTRJ6TkVb+HFsp9fHhzTJPKm/Xq bbQT/iLzu7/Xjy2DteSjxJQtv9j7ViEQA+iJuGKHldN8M+me0xH6HbaHkvpV+IfPOp 8V+Fi3qgPdsew== From: Kees Cook To: Bill Wendling Cc: Kees Cook , nvdimm@lists.linux.dev, Alison Schofield , Dave Jiang , Greg Kroah-Hartman , Guangshuo Li , Ira Weiny , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Vishal Verma , Andy Shevchenko , Steven Rostedt , nikitash.mariiaw@gmail.com, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v3 10/11] nvdimm: ndtest: Return the string length from flags_show() Date: Wed, 30 Sep 2026 16:52:38 -0700 Message-Id: <20260930235247.157921-10-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260930235231.out.387-kees@kernel.org> References: <20260930235231.out.387-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=1145; i=kees@kernel.org; h=from:subject; bh=2AtxDeGumxoxvmY3xbTN0AxqV9yj2Kg5m9bB3ZVwy3c=; b=owGbwMvMwCVmps19z/KJym7G02pJDFl7FxwTmX25ulfl/vcZB6YynW2bmyn+PmUDl2XFr2flH LM8/55f2VHKwiDGxSArpsgSZOce5+Lxtj3cfa4izBxWJpAhDFycAjCRr88ZGVasO+8UUHK59DD3 lEe1/2In7qytkDDcGuQ4+cyvh1mNk8MZGS6v0DisYbDkstRFa7XALaanIuISFsa+VdW2jWXOefL vDBsA 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 --- 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