From patchwork Wed Sep 13 19:38:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 13383711 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AAEBEE020B for ; Wed, 13 Sep 2023 19:38:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232488AbjIMTit (ORCPT ); Wed, 13 Sep 2023 15:38:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54572 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232334AbjIMTit (ORCPT ); Wed, 13 Sep 2023 15:38:49 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48DF41998 for ; Wed, 13 Sep 2023 12:38:45 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d7b957fd276so256762276.0 for ; Wed, 13 Sep 2023 12:38:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1694633924; x=1695238724; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=5D9cmGNnxZclEaUPRp7dDRkIa3NaBWA/5YbPgcSOdlU=; b=FLlzdeFavhqlzy4MC1JUgkhtQCIAqORJqP4YlKTbXRHHW4SDPUKHATV5MG7sWtoqyw JlOk3w3zl5eiGAfXS3M3FGmu4NefugskyB0wyPlnHqKdpRKDM9trNLQkOF5sP1b9JFfp KwMvVJWqug/Q7aEmu8arEKEGdzhl2pRpVZ/twXErX9CSaUC7i1cx9nhoJvZanZM8Vb4E eWt8veY6YDfVS8EGtK3LT0OLIddNGlWCJBnW8Y1DF/dCIe0tIpMHRgOLRj//eQCr55jy yrEW/Qadkl2zT1V/439SdGxhci5KOcuulo7OIwwAgw0Bb6+75oyxGOXn6GjYg6FPqhlc Nd5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694633924; x=1695238724; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=5D9cmGNnxZclEaUPRp7dDRkIa3NaBWA/5YbPgcSOdlU=; b=JkFvuWx6V93L2SqNlEZ7E+Vmw46m/H9OUfs2ILgX0v6BbUSXDU5J+6JPzBQIt7OJ9A Ez6qocJ4Q+Ph9VSFsa1tSD7sYADQWjOpIfPlG5SANdOM/GwO9fURRGH+33hpuspetm/2 8H/yMK27T0gYS6AuFejB+bqyCoMjZnGeMCGuFP3THtnGCLv76UklE6sUmcQCxno5oDYo JVx+KqjBZrxSj1HQy9ljYS1uN7jNKCkHib/YGB6WHRp6rwrJzG9I41z0iMcRCwqN6vCW t0EQH50z8gwnffITZXXlFD0P+EhAqxnUrmCwKmZ6+h2eXaMYGA0I/LrNKxuLd8YWuZ0j h52w== X-Gm-Message-State: AOJu0YyaJ3WK71ZS8NhiWlPmqNoVPtpmXxjSe1UiCGxHUNpZ/OJlmiv7 4XG9HMdwzqbqcVJPolAVSkEGn77JN5wOeRyzCA== X-Google-Smtp-Source: AGHT+IH31Zv0S2pEtOg8E5M6+3MG2ReqXhMlUlaKfNdDCbhIRCrg8Sj/H6HMaMvc1v62WHB41McV9U9S28iHMvwAYA== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a25:41ca:0:b0:d77:f6f9:159 with SMTP id o193-20020a2541ca000000b00d77f6f90159mr78122yba.9.1694633924538; Wed, 13 Sep 2023 12:38:44 -0700 (PDT) Date: Wed, 13 Sep 2023 19:38:44 +0000 Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAMMPAmUC/x3NPQ7CMAxA4atUnrGUJkUIroIY8uMEDw2RXQqo6 t0bMX7LexsoCZPCbdhAaGXlV+0YTwPEp6+FkFM3WGOduY4OdZEa2w+T8EqimFnmjxfChYp4DG1 umCi8S1aMeJ7yJXifnY0GerMJZf7+f/fHvh9c242qfwAAAA== X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1694633923; l=1807; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=tFl2PNzqL8STywNv0UTNztdqinU7Ek8sPp6wO3F9Txw=; b=Qx9x2TQmkLa2oDNyG2+vl9LZXozyDkyNECZv70nQl8TbYysev2y1AlZud6Hv+kgnjZSkpklKS SwXrDu/ddO6AXv7TOSpT/PXQeIdImLO9VBF1J2iLFHssovmlcAAlMxf X-Mailer: b4 0.12.3 Message-ID: <20230913-strncpy-drivers-firmware-tegra-bpmp-debugfs-c-v1-1-828b0a8914b5@google.com> Subject: [PATCH] firmware: tegra: bpmp: refactor deprecated strncpy From: Justin Stitt To: Thierry Reding , Jonathan Hunter Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org `strncpy` is deprecated for use on NUL-terminated destination strings [1]. We should prefer more robust and less ambiguous string interfaces. It seems like the filename stored at `namevirt` is expected to be NUL-terminated. A suitable replacement is `strscpy_pad` due to the fact that it guarantees NUL-termination on the destination buffer whilst maintaining the NUL-padding behavior that strncpy provides. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook --- Note: compile tested only. --- drivers/firmware/tegra/bpmp-debugfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec change-id: 20230913-strncpy-drivers-firmware-tegra-bpmp-debugfs-c-54f7baaf32c0 Best regards, -- Justin Stitt diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c index 6dfe3d34109e..bbcdd9fed3fb 100644 --- a/drivers/firmware/tegra/bpmp-debugfs.c +++ b/drivers/firmware/tegra/bpmp-debugfs.c @@ -610,7 +610,7 @@ static int debugfs_show(struct seq_file *m, void *p) } len = strlen(filename); - strncpy(namevirt, filename, namesize); + strscpy_pad(namevirt, filename, namesize); err = mrq_debugfs_read(bpmp, namephys, len, dataphys, datasize, &nbytes); @@ -661,7 +661,7 @@ static ssize_t debugfs_store(struct file *file, const char __user *buf, } len = strlen(filename); - strncpy(namevirt, filename, namesize); + strscpy_pad(namevirt, filename, namesize); if (copy_from_user(datavirt, buf, count)) { err = -EFAULT;