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 15DD84CEE55; Mon, 5 Oct 2026 15:57:20 +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=1791215842; cv=none; b=o608G2UiZDRYSbV4jculFRNqO/43Npx1t6RJeosZU6bXm2CtpLYA4b1We16qdet5aIkw76GmXsNfJzMdDjJZjL0Rv7SfpmgzqUe0y3XdhlGbI2KlnVX1fcV5U1+6TXMBHK5fQdI8wiKBuj/S8G42IhHy58/ZoCDG/vc4HFtoBFA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791215842; c=relaxed/simple; bh=83ejdE21ZGKoH4IcbNOtIYCWNlvKIrQjgUzARamzwfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dOSYRqZdg6oJWsmwPfdIM/CiKWk2jXcXOMb3tz8dgIPgQsEoPNViVrK2q27JbBeUiv5i9u17Flbw2KCqASXcxbYr5+uI/zHvTkuozMkLeDMY8F/H0yHF6+OsSi6oxvK93KO17rm3sycc6caiRjhKtr3e3vuD8sNy3ryqOcfZMGE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B/jfaiKY; 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="B/jfaiKY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 024B21F008A4; Mon, 5 Oct 2026 15:57:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791215839; bh=3OTiHc1/0syaVTh9plxPSwZX9JA+w6f18TNYUs4mWiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=B/jfaiKY1DaVksZkgxRP+KtV6co/Ste4zyrEZxOM09D8nw6Y1WUggA+HHzHyLLijI h+iUxjh/eEX3rPqeH4Hh7JRFwgF+YkaupsynORwDpANIaPTcZRFn3xq/ZffqFlkPF0 ez6ddGkV3Yq5BqNRUqpIAnVBWWf29NKLt/iJI0EVW5MD7vFE5caqLQ5hSudSpMQKX0 vH3jA1sTxjFkXGfC2tQwruEMV1EZ47F3C/weCUVYHykrn0gpJXlfjWL0TPcUnrV8dX vFmLtl3pCjYiLUQSXKdxnlZ6utHw7bFHRUGsaPg4qYLJXssSxzpXrxHOI/Fxw3zOpf iSr4oZ4FITEEA== 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 , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v5 11/12] nvdimm: ndtest: Return the string length from flags_show() Date: Mon, 5 Oct 2026 08:57:01 -0700 Message-ID: <20261005155708.1471260-11-kees@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261005155653.late.426-kees@kernel.org> References: <20261005155653.late.426-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=1205; i=kees@kernel.org; h=from:subject; bh=83ejdE21ZGKoH4IcbNOtIYCWNlvKIrQjgUzARamzwfE=; b=owGbwMvMwCVmps19z/KJym7G02pJDFmHT5wVeXHJcdntO9XMGvYpzF/r2O8cPCBXN+9LzCquy qNb9D6s6ShlYRDjYpAVU2QJsnOPc/F42x7uPlcRZg4rE8gQBi5OAZjI59eMDNPeM56e67P6w2qX XWWTJ2Um39uS9cSg3rrP8pag6JNXrzsZGSYlC6iuNvfntZijP8H4gufTzpD0i1FxulcXTrzNzu2 gzQYA 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 Reviewed-by: Alison Schofield 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); -- 2.55.0