From nobody Fri Dec 19 06:32:42 2025 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 E44D7E7D0A2 for ; Thu, 21 Sep 2023 19:46:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231300AbjIUTqW (ORCPT ); Thu, 21 Sep 2023 15:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231299AbjIUTqA (ORCPT ); Thu, 21 Sep 2023 15:46:00 -0400 Received: from mail-vs1-xe4a.google.com (mail-vs1-xe4a.google.com [IPv6:2607:f8b0:4864:20::e4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57C6E8C60F for ; Thu, 21 Sep 2023 12:06:12 -0700 (PDT) Received: by mail-vs1-xe4a.google.com with SMTP id ada2fe7eead31-4525d1075afso585277137.2 for ; Thu, 21 Sep 2023 12:06:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1695323164; x=1695927964; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=mEI/FE0LzaOE8LB3j/EPmAsW/lNDHZXMlP+MK6JtiH0=; b=T4G0kmwnn9rWTNvn8r2laozFkLhliepsTuDpdqRkt90vr/1TMPlBX/6MxSlikmVAe2 JfgOzgVxmSVc6mA1Z7tJbtRalOhTIqNHPCM+iinXGRHISUhM/bKzd0WGfu08R2un+ai6 eAKklVIGPMDKR80CaPO2PufRmHuUYkE8/EOoFXu2ZtP7Ek0CYhqVLVWJDTg33OlTrx3o 7+aodDsuyhyloG0HA2KoegLM1WkynRQJBjkWTpS+PZxjEqAn4aSBA2xAGIm7J5D8f5Bi n5Fxe2muC9GDfqR1ZP44CQkV0XMciatLz2eGnQxyrDlyJDF6G+sk/MMF38UHmitxGHNl YN5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695323164; x=1695927964; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=mEI/FE0LzaOE8LB3j/EPmAsW/lNDHZXMlP+MK6JtiH0=; b=a1kWlucIVzqeMnUa7rxu0jT+nOP4jeE0qlDAg3KUVI4v/9DoYCCphzrYW7exG7w5KM ppaRf30S6MJjPUQhLSRVeA48dLd7isYVaNcpjJBLjg1I3lHPQEb11wG7ndhez6gLEHiD NtCHdFa/Tefx+kkfBsRAbdldhnMe4rNIqfu9QRvw8PSidlj2MZkB1zUMcYm6jfoMkLUU PhbtwYddtPexTjGn0boWTR6P7SN+rj36FyTh4LfR4xWXcs3dAoZ4XxS2ATthnXMQEGaJ XHMdF8tQohsxg1a9kcAh6nKeQrDx1ACRNLArr+UW/G2z+Wv5jn9z705zZXK3vJEOar9H kx8Q== X-Gm-Message-State: AOJu0Yya5CdmnGutYZ+mH8JAkgBZd6sOuVa7ZW6HZcordKaSUmq0elAe mh1jPndhfRW+KwURzKDq0XxFbSrabSjpBzwARg== X-Google-Smtp-Source: AGHT+IEYzveRK4DpKaBvTcozNvLOzlrpzzHF+TShyi7tBIAI7apmqP3Y8DUHUTwq86i/Sw1IZExa+IRloVCK7eDaOg== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a25:848e:0:b0:d82:9342:8627 with SMTP id v14-20020a25848e000000b00d8293428627mr63851ybk.6.1695268265522; Wed, 20 Sep 2023 20:51:05 -0700 (PDT) Date: Thu, 21 Sep 2023 03:51:04 +0000 Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAKe9C2UC/x3MwQqDMAwA0F+RnA3Yyg7dr4iHkGYzB7uSFNkQ/ 33F47u8E1xMxeE5nGByqOundIRxAN6ovAU1d0Oc4jylGNCbFa4/zKaHmKPOjDt5E0PGnCQ8IqV ATNCLavLS790v63X9AcxwdSxuAAAA X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1695268264; l=2236; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=xRRL8ZZagoPuEYpnmLvMHfqr3+/4b42z9ovF8TORhlE=; b=pVohjE+m58JPvLT2c72pPRI1bHXV2c7QOlM9qXaA2xrrnFGjQsCWYX+d7O882U2GpU1hdFZVW yLLUEfbE8+rDkX3sbp6f/QeKPamXfHchETunk7iwfC0o7f3mbtu7FJs X-Mailer: b4 0.12.3 Message-ID: <20230921-strncpy-drivers-i3c-master-c-v1-1-9fdb8d8169e1@google.com> Subject: [PATCH] i3c: replace deprecated strncpy From: Justin Stitt To: Alexandre Belloni Cc: linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt Content-Type: text/plain; charset="utf-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable `strncpy` is deprecated for use on NUL-terminated destination strings [1]. We should prefer more robust and less ambiguous string interfaces. We expect adap->name to be NUL-terminated based on i2c_adapter name use: | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); NUL-padding does not seem to be required as `master` is zero-allocated and `i3c_master_to_i2c_adapter` simply returns a field from within `master`: | master =3D devm_kzalloc(dev, sizeof(*master), GFP_KERNEL); ... | struct i2c_adapter *adap =3D i3c_master_to_i2c_adapter(master); ... | static struct i2c_adapter * | i3c_master_to_i2c_adapter(struct i3c_master_controller *master) | { | return &master->i2c; | } This means that `adap->name` should already be filled with NUL-bytes. Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncp= y-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.htm= l [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook --- drivers/i3c/master.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 87283e4a4607..8573ca507708 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -2309,7 +2309,7 @@ static int i3c_master_i2c_adapter_init(struct i3c_mas= ter_controller *master) adap->dev.parent =3D master->dev.parent; adap->owner =3D master->dev.parent->driver->owner; adap->algo =3D &i3c_master_i2c_algo; - strncpy(adap->name, dev_name(master->dev.parent), sizeof(adap->name)); + strscpy(adap->name, dev_name(master->dev.parent), sizeof(adap->name)); =20 /* FIXME: Should we allow i3c masters to override these values? */ adap->timeout =3D 1000; --- base-commit: 2cf0f715623872823a72e451243bbf555d10d032 change-id: 20230921-strncpy-drivers-i3c-master-c-d9e152a91aca Best regards, -- Justin Stitt