From patchwork Wed Oct 11 21:48:39 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Stitt X-Patchwork-Id: 13417995 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 2767C2230D for ; Wed, 11 Oct 2023 21:48:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wsL7rKbs" 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 4C8A7AF for ; Wed, 11 Oct 2023 14:48:41 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d81646fcf3eso371643276.0 for ; Wed, 11 Oct 2023 14:48:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697060920; x=1697665720; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=Fmgja0bLa+jteMFhSajUsHxegsUDbMvKhEZglRqt45Q=; b=wsL7rKbs/MulTCGq7SLJxQqpb+ep5Soiu+13mphubbPnPScNBdl4FUKSdjQNnLGZsd JxE+cMV2D/PELRJTwMJna7YWX1QtrIxpUBb/ZZUn60pokcKtxREydkv69xLgZdRtDjRa rmy4XCKskBB0ZY80ZA18i9vXWwS51ZAPRQPjJJDiqdtimvb09w+FMsWiVMG1lbwVFlqf a3it/hR317J48b2nwFksgweF1h+PqcsjCRATItiS7TAM2gSbTWgVMLzaaAq/ail5JRxg fKErnlMz5RTtH7GBfo6Nv5JSH5FnqyQgWLIJZmchCtfTTApDBnCKn9F5BfGZ8+dLjhlo C14Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697060920; x=1697665720; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Fmgja0bLa+jteMFhSajUsHxegsUDbMvKhEZglRqt45Q=; b=ri4SE2jaRDSqMLAcs0CGWB/MTP3WB24yPHa2m/up+eYo6USkljyTfcxm3GFQ/9VcMN AfZs9PM9qmg7CNVJaiad5xtVncr7tZfoP2ka4KO1myYXkJZIah2859WRdzPXguS0pvFZ h6D2wycwtjaNmFMKtupBUPLE0AMfHjx17//1IlidU6zhrd9apIFmI8ZJnTyI5UVEKdH4 9GLd/avpzLsmvI+xm0NxgTUsPyMU9vDUQSpt9Yn5cTzSRGOii1zctbxC0txW4EMPnrGS rLnj/GAKxxygjutMKZjO+5wFlWGnUUNwCh/qi8O9kYv5pJYBTjoq0WJ/Y+uSgNVjMxGJ 6yzw== X-Gm-Message-State: AOJu0YyuQT4Y3M/7jVVooRhEUVXkglyuc6kUkIxXJnFACklZhjs56ht5 nxiPf8mJSdd1XVWUZxKYQan6HFHn9lsqyS2DLw== X-Google-Smtp-Source: AGHT+IGJoTG4b7zDPCsibXJpxnlw6jNvBvSJLdFkY2BSvTdOPSvUCRCdC6zVI4G66sLlVvOY3vTtDT7UkI8II5FbKQ== X-Received: from jstitt-linux1.c.googlers.com ([fda3:e722:ac3:cc00:2b:ff92:c0a8:23b5]) (user=justinstitt job=sendgmr) by 2002:a25:870c:0:b0:d9a:3a25:36df with SMTP id a12-20020a25870c000000b00d9a3a2536dfmr177263ybl.8.1697060920492; Wed, 11 Oct 2023 14:48:40 -0700 (PDT) Date: Wed, 11 Oct 2023 21:48:39 +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=H4sIADcYJ2UC/x2OQQrCMBBFr1Jm7UAnRSxeRUR0MrFZOAmTtCild zft4sF7q/9XKGJRCly7FUyWWGLSFnTqgKenvgWjbw2udwP1RFiqKecfeouLWEGVilInsV0aljR 9BDXkHU52+MOkpNlYkJFGcq9xOF8Ce2g72STE7/Hhdt+2P37e/baTAAAA X-Developer-Key: i=justinstitt@google.com; a=ed25519; pk=tC3hNkJQTpNX/gLKxTNQKDmiQl6QjBNCGKJINqAdJsE= X-Developer-Signature: v=1; a=ed25519-sha256; t=1697060919; l=2791; i=justinstitt@google.com; s=20230717; h=from:subject:message-id; bh=d1CwcSoXBknLIhkv+OR1VBIGF8nQz/k16YwYlTdC9Ds=; b=OX8CmXZpnCy8ywuesrOENMy2j4fqvuDPmBTZziT688Z17/BOW8xmijt701YYwPkN1Ws6XyooM RgXZMOR098sC456O0B2+zgQidajVjXgp6fBUqs2vZ/7XEhUvTT2W3s/ X-Mailer: b4 0.12.3 Message-ID: <20231011-strncpy-drivers-net-ethernet-netronome-nfp-nfpcore-nfp_resource-c-v1-1-7d1c984f0eba@google.com> Subject: [PATCH] nfp: replace deprecated strncpy with strscpy From: Justin Stitt To: Louis Peens , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni Cc: oss-drivers@corigine.com, 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_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable 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. We expect res->name to be NUL-terminated based on its usage with format strings: | dev_err(cpp->dev.parent, "Dangling area: %d:%d:%d:0x%0llx-0x%0llx%s%s\n", | NFP_CPP_ID_TARGET_of(res->cpp_id), | NFP_CPP_ID_ACTION_of(res->cpp_id), | NFP_CPP_ID_TOKEN_of(res->cpp_id), | res->start, res->end, | res->name ? " " : "", | res->name ? res->name : ""); ... and with strcmp() | if (!strcmp(res->name, NFP_RESOURCE_TBL_NAME)) { Moreover, NUL-padding is not required as `res` is already zero-allocated: | res = kzalloc(sizeof(*res), GFP_KERNEL); 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. Let's also opt to use the more idiomatic strscpy() usage of (dest, src, sizeof(dest)) rather than (dest, src, SOME_LEN). Typically the pattern of 1) allocate memory for string, 2) copy string into freshly-allocated memory is a candidate for kmemdup_nul() but in this case we are allocating the entirety of the `res` struct and that should stay as is. As mentioned above, simple 1:1 replacement of strncpy -> strscpy :) 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 Reviewed-by: Kees Cook Acked-by: Louis Peens --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231011-strncpy-drivers-net-ethernet-netronome-nfp-nfpcore-nfp_resource-c-1812b8357fcd Best regards, -- Justin Stitt diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c index ce7492a6a98f..279ea0b56955 100644 --- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c +++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.c @@ -159,7 +159,7 @@ nfp_resource_acquire(struct nfp_cpp *cpp, const char *name) if (!res) return ERR_PTR(-ENOMEM); - strncpy(res->name, name, NFP_RESOURCE_ENTRY_NAME_SZ); + strscpy(res->name, name, sizeof(res->name)); dev_mutex = nfp_cpp_mutex_alloc(cpp, NFP_RESOURCE_TBL_TARGET, NFP_RESOURCE_TBL_BASE,