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 8531738AC90; Sat, 3 Oct 2026 03:59:25 +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=1790999968; cv=none; b=bel8DiA0M4J7g+vkOs2say0O4/YN13QBBf/hH/HgbcGuNsqgdh/Q9XriXnR3WwIcUNdLes8FcCxMths6F8vniCLn9rsVxLAjlbEMqDMI/GwO7NSlbAI8Nnb3JTfieWDMz5/pM2WNFWxHU/A29wzd4DcW4Ba+vEYA58aLq4p5uQk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790999968; c=relaxed/simple; bh=83ejdE21ZGKoH4IcbNOtIYCWNlvKIrQjgUzARamzwfE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=okYv+OskvnVAl+jXo1f4Ii4hadiBvDTjpcPqqtJbZL+L7nHpwEcehQsYp0MljFKiAWds/6SmfnGKmWCeDgfN9k1MD6qGxXfzbQ6pIsTJIaq3ADliwZZaHXlmOgMl6caA4a28Wz51grdpJBtHn+7vJoa+SHay37ioC7LKvuzzu10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=esNzDwkF; 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="esNzDwkF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 048601F008A2; Sat, 3 Oct 2026 03:59:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790999962; bh=3OTiHc1/0syaVTh9plxPSwZX9JA+w6f18TNYUs4mWiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=esNzDwkF/ZPzuVHUwOX/wWg1G8q95GJofpLCNZ8CqjZQ3tSrgZVSe0wl0i/6tgYuB b+Og8ah3xsZ8t9cxtea4sG661YTsOMgK8WVA8wpEoh1BTI8kBHx36q6v+G2wPY7mPx z4I5y1NwZKx3SFzjqzalrK3VNGzGzXi+Mz5t8hh+znJCYY/w/7zYGnJf7LEk0Ev38H z5LVKQGZpj2BeyE843ig3p7wNG9C7eq7HmfrKRy6iuRy1T6I4c49+fSOADaKVkxXWO kl9SSeOeX8e292rsoebDYCW364bXxFepgepHcQXFCiqAipN3wEtdDK2FQylf72d8Ko +8U5XvTRO77ng== 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 , Jonathan Corbet , Andrew Morton , David Gow , Petr Mladek , Sergey Senozhatsky , Shuvam Pandey , Steven Rostedt , =?UTF-8?q?G=C3=BCnther=20Noack?= , "Matthew Wilcox (Oracle)" , =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= , Masami Hiramatsu , Mathieu Desnoyers , Jiri Kosina , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , "Christophe Leroy (CS GROUP)" , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Shivaprasad G Bhat , Thorsten Blum , Randy Dunlap , Shuah Khan , linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v4 10/11] nvdimm: ndtest: Return the string length from flags_show() Date: Fri, 2 Oct 2026 20:59:15 -0700 Message-ID: <20261003035921.1918874-10-kees@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261003035906.too.263-kees@kernel.org> References: <20261003035906.too.263-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/KJym7G02pJDFkHaieLvLjkuOz2nWpmDfsU5q917HcOHpCrm/clZhVX5 dEteh/WdJSyMIhxMciKKbIE2bnHuXi8bQ93n6sIM4eVCWQIAxenAEzEo5Thf0HjJa6f2wWCLz5Z ndCTresx5Vpd30Jz8x/NP1assHW/ZMzwT78//eJ0f787O6pSOef+ZToVzRjHcTRt/ZT+eYtmCc4 o4QUA 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