From patchwork Mon Oct 23 19:33:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe JAILLET X-Patchwork-Id: 737327 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 AC9051CF86 for ; Mon, 23 Oct 2023 19:33:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wanadoo.fr header.i=@wanadoo.fr header.b="migciIyc" Received: from smtp.smtpout.orange.fr (smtp-23.smtpout.orange.fr [80.12.242.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7864F94 for ; Mon, 23 Oct 2023 12:33:26 -0700 (PDT) Received: from localhost.localdomain ([141.170.221.62]) by smtp.orange.fr with ESMTPSA id v0fzqGEQclciav0fzqWHCB; Mon, 23 Oct 2023 21:33:24 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wanadoo.fr; s=t20230301; t=1698089604; bh=MlLlyO5nmPmV+Of5dabISHH05s0yAgNbg1lqfnhBiDo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=migciIycEHHxVSLdlbD0OWW2VjQcd388g4a4U6rPubKQtgb7HRtjFpJ689ZOdUYfJ M4DjVn6rYm2JxOdyf/1Iv8L43HNqSsvwlKONI+C/7GXglHEqf3PJXDuA3QavdkyrQe p0Ub2Cah2/euUBdqZnOBr/06U7KJDK+7wDHYJSYKqMN/EVMycRrdJPzEBvRfg6sLz0 ToJ4IBNGuk04t0PpFcPhck9S0I+d+73KNfWr+J7PcswUyNqVpMLLYXM5F9DJ9f2cL/ ud6XVZF0TjAnFY3ldTZLfVSVJjXUzRrKUTjGqr+mM6UaMwgZKN2dc0NXOComv7RoB8 kDofSZJzzAWWg== X-ME-Helo: localhost.localdomain X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Mon, 23 Oct 2023 21:33:24 +0200 X-ME-IP: 141.170.221.62 From: Christophe JAILLET To: rafael@kernel.org, lenb@kernel.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET Subject: [PATCH 2/4] ACPI: sysfs: Fix a potential out-of-bound write in create_of_modalias() Date: Mon, 23 Oct 2023 21:33:16 +0200 Message-Id: <004a9aa85dcc37d112443e133c9edfd7624cd47b.1698081019.git.christophe.jaillet@wanadoo.fr> X-Mailer: git-send-email 2.32.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The remaining size of the buffer used by snprintf() is not updated after the first write, so subsequent write in the 'for' loop a few lines below can write some data past the end of the 'modalias' buffer. Correctly update the remaining size. Note that this pattern is already correctly written in create_pnp_modalias(). Fixes: 8765c5ba1949 ("ACPI / scan: Rework modalias creation when "compatible" is present") Signed-off-by: Christophe JAILLET --- drivers/acpi/device_sysfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c index 4deb36dccb73..7ec3142f3eda 100644 --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -215,6 +215,8 @@ static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias if (len >= size) return -ENOMEM; + size -= len; + of_compatible = acpi_dev->data.of_compatible; if (of_compatible->type == ACPI_TYPE_PACKAGE) { nval = of_compatible->package.count;