From patchwork Thu Oct 12 21:20:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 13419824 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 C1349358BA for ; Thu, 12 Oct 2023 21:20:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="XkLaD7X7" Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7DDE4BB for ; Thu, 12 Oct 2023 14:20:05 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-59f61a639b9so21839797b3.1 for ; Thu, 12 Oct 2023 14:20:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697145604; x=1697750404; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=Hnx2hMUROy5hPaWMuQS6wGUcTD4C+Y8X52y6T46QNnk=; b=XkLaD7X7q8fkKutL6vUFBc68A+tAQ9/sIOS21rjfw57sGiz+TOYsD85qQSv+C2xgxb lQDhbPztXnHeZES2/gdkdSUtRMUy8REZ4UJFj9Wo4iRMZ84Dd5/liVwuL3Qa1TqBW3BH jlpV7rdPPrLIYATw07Jk3evdgmyuXvzIHkEGEk1MHCN+1ZQ+EE4jMRSvwSBWHHzOEPAk j1ScvGrYxWsfh5SFjmTTKze7NVdYdnL+tG8UWmick/5GdFthB9vlwYaNSPzlI2hnWGs9 EfgIFe99jOKuRqoGvITo5UTaq3jlPGHSrrVVVCoAM0y2QIbIcL9a34qRo7VFpnpf7FAi zQ5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697145604; x=1697750404; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Hnx2hMUROy5hPaWMuQS6wGUcTD4C+Y8X52y6T46QNnk=; b=KwnOr3CKLY7uVi6HNSkPjsR7EC3hr6JST1McOAylRMYYQNdp/HEt0HbcuFqTdcpC7E I84W67imjq9ycff6ezNxXfuOJBJdduoQ9lsFDlZVLG27tfXwCnm1AQQr5LJ89shhBwbF pGTdXeYuKdfWfd7Tprl4l0sTJqOE76xHrTAo8HzQ5oeljABvROex53aCzSe9oR4cRYPB AbQow8ACKneUtCgdonsdRO2Ikq74I/GtABPlaoHJKs1ias9tAJd7Di9jmIy0vpUWV4/L mbbVhD0bfxSIq/QuVzSU6HhehG9UJgMpvBhkRGbYgAu/Nro5lCyFNqcc5WoXgAvoomvF QHHg== X-Gm-Message-State: AOJu0YxwNF3CCRnz7W2zhbjz2siT/J4OyoGUR2QIRPstIkmDhC/xLok1 00JC3bHU5XsvI/meVmynIOgnfCB5n5uO3OknTg== X-Google-Smtp-Source: AGHT+IGEz38HdWBwXZW+qHolz7YTUuV4PlFesGO+loEhl5nFIdEKYX6auuR5XKLavYAKjeNoVukACpRoPzbikawFBw== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a81:af27:0:b0:5a7:b54e:bfc1 with SMTP id n39-20020a81af27000000b005a7b54ebfc1mr243135ywh.10.1697145604749; Thu, 12 Oct 2023 14:20:04 -0700 (PDT) Date: Thu, 12 Oct 2023 21:20:04 +0000 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAANjKGUC/yWNQQ6DMAwEv4J8rqUkFRe+UlVVCAZ8qIvsFFIh/ t60XFY7h9ndwUiZDLpmB6WVjV9SwV8aSHOUiZCHyhBcuHrnA1pWScsHB+WV1FAoI+WZ9Fe2apS 3YC5TT2c+npEFE7rWt6GPY0zBQV1flEYu/+fb/Ti++Q+lF4kAAAA= X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1697145603; l=2721; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=K5JHCGxkEZHPygsVoHqfoDZGkV0pxG6IhwPB2u479/U=; b=bsjP3OcLje0SPvVnGKRcZtcvFRKAeLjmhv0CkhKsA5enluy6XHRLQ3iodA/qzFgN/6BR552D8 h2380adLrRVA7mWJ7s69+bGSfcNmC0XDqvDOKG9KsHHWLGb/SSqaOQU X-Mailer: b4 0.12.3 Message-ID: <20231012-strncpy-drivers-net-ethernet-wangxun-txgbe-txgbe_main-c-v1-1-c9bb3270ac98@google.com> Subject: [PATCH] net: txgbe: replace deprecated strncpy with strscpy From: Justin Stitt To: Jiawen Wu , Mengyuan Lou , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. Based on usage part_str usage within txgbe_read_pba_string(), we expect part_str to be NUL-terminated but not necessarily NUL-padded: | /* put a null character on the end of our string */ | pba_num[10] = '\0'; Interestingly, part_str is not used after txgbe_read_pba_string(): | ... | err = txgbe_read_pba_string(wx, part_str, TXGBE_PBANUM_LENGTH); | if (err) | strscpy(part_str, "Unknown", sizeof(part_str)); | | netif_info(wx, probe, netdev, "%pM\n", netdev->dev_addr); | | return 0; | |err_remove_phy: | txgbe_remove_phy(txgbe); |err_release_hw: | wx_clear_interrupt_scheme(wx); | wx_control_hw(wx, false); |err_free_mac_table: | kfree(wx->mac_table); |err_pci_release_regions: | pci_release_selected_regions(pdev, | pci_select_bars(pdev, IORESOURCE_MEM)); |err_pci_disable_dev: | pci_disable_device(pdev); | return err; |} ... this means this strncpy (or now strscpy) is probably useless. For now, let's make the swap to strscpy() as I am not sure if this is truly dead code or not. 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#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/net/ethernet/wangxun/txgbe/txgbe_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231012-strncpy-drivers-net-ethernet-wangxun-txgbe-txgbe_main-c-05152bafac20 Best regards, -- Justin Stitt diff --git a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c index 5c3aed516ac2..c795fbab37be 100644 --- a/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c +++ b/drivers/net/ethernet/wangxun/txgbe/txgbe_main.c @@ -739,7 +739,7 @@ static int txgbe_probe(struct pci_dev *pdev, /* First try to read PBA as a string */ err = txgbe_read_pba_string(wx, part_str, TXGBE_PBANUM_LENGTH); if (err) - strncpy(part_str, "Unknown", TXGBE_PBANUM_LENGTH); + strscpy(part_str, "Unknown", sizeof(part_str)); netif_info(wx, probe, netdev, "%pM\n", netdev->dev_addr);