From mboxrd@z Thu Jan 1 00:00:00 1970 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 34B0BC8EE for ; Wed, 15 Nov 2023 10:14:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=resnulli-us.20230601.gappssmtp.com header.i=@resnulli-us.20230601.gappssmtp.com header.b="u9Og2uP3" Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 24F919C for ; Wed, 15 Nov 2023 02:14:45 -0800 (PST) Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-53df747cfe5so10221453a12.2 for ; Wed, 15 Nov 2023 02:14:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20230601.gappssmtp.com; s=20230601; t=1700043283; x=1700648083; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=NUrvNnPjdmhN7swaMdYslu65aOtTlRA+U1vSW8EoaqY=; b=u9Og2uP3wIarceH4HtckW8iejQtrJdHJOxvZ9DLVC25mZhFzcnGVCiwQigP+209wkw y3d9/yPNSwbvXzQPlQqQuyA1EIkD5D+TnFhgtxnC4MFHLhL6t2ULWQ1GxS2L91TytVID 0IrvyiCYlWlx4nBLWw8RmKX5y6gcQKXsVpvN5/xZwm8txyJBACFEwLVkYTnrzO4Gglf8 vfDbyb4rk1A3ch7uW9zkJPt26UAsZyKeb5v+9sRAz/wQ2m8XyA2P2V0iKzXJ+VUho6dB u0kZinbSVkKmGli3nM6v+dQLxlHJZHMIiSFa7+11zzhc2zx+deUzxCH82hNIq+P2lgrK dabQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700043283; x=1700648083; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NUrvNnPjdmhN7swaMdYslu65aOtTlRA+U1vSW8EoaqY=; b=gxgl4qdQ9+WmQxxLBy3vlRRK9tryzyoRJMCK6H7yiGQnNqHbGNUqHpJ4kzxGp093to Nhd6HGb+y22ph+JHnQTIprNHY3o9gzZ5ZBxjMva2qTcFBpfmOJxcSEYK/m35PV0NTQu5 nx1J/dBfiW65VtQF0opmJEas9U4M+Gu0NnKDrqjQhq2Azj2bvaZcjs2kexIZHREQyrF3 sGhPhXjQwyXkSsLnzYOF/Dj4i5x1Lsf4fhBsb9KDqET0jGwQr4Ce2W+icm5JLt+ehUDS JBKfE52GhPTorieGbO4L5uRnleK9mxU9IA8rZwTRQTsZD1d1rLswKKkVRHx0GVzGqhxm 8JbQ== X-Gm-Message-State: AOJu0YygRPlU9u/b2+VBFoqBI6vk+/reBhH4b0GREEOcyxx9Y0fVvRnd Aln7ol9zLFqBbr9DCvT/r2/ERg== X-Google-Smtp-Source: AGHT+IFpFi1fqB5PmI7Ayyou3rQK1sZt3rFJX8kzjZoMvwHdWTBN6GL4WvelgABRuPaJUcfwlXWOoQ== X-Received: by 2002:a17:906:bc99:b0:9d7:1388:e554 with SMTP id lv25-20020a170906bc9900b009d71388e554mr8727360ejb.17.1700043283423; Wed, 15 Nov 2023 02:14:43 -0800 (PST) Received: from localhost (host-213-179-129-39.customer.m-online.net. [213.179.129.39]) by smtp.gmail.com with ESMTPSA id dt10-20020a170906b78a00b009a5f1d15644sm6753687ejb.119.2023.11.15.02.14.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Nov 2023 02:14:42 -0800 (PST) Date: Wed, 15 Nov 2023 11:14:41 +0100 From: Jiri Pirko To: Gal Pressman Cc: "David S. Miller" , Jakub Kicinski , Eric Dumazet , Paolo Abeni , netdev@vger.kernel.org, Simon Horman , Vlad Buslov Subject: Re: [PATCH net v2] net: Fix undefined behavior in netdev name allocation Message-ID: References: <20231114075618.1698547-1-gal@nvidia.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231114075618.1698547-1-gal@nvidia.com> Tue, Nov 14, 2023 at 08:56:18AM CET, gal@nvidia.com wrote: >Cited commit removed the strscpy() call and kept the snprintf() only. > >It is common to use 'dev->name' as the format string before a netdev is >registered, this results in 'res' and 'name' pointers being equal. >According to POSIX, if copying takes place between objects that overlap >as a result of a call to sprintf() or snprintf(), the results are >undefined. > >Add back the strscpy() and use 'buf' as an intermediate buffer. > >Fixes: 7ad17b04dc7b ("net: trust the bitmap in __dev_alloc_name()") >Cc: Jakub Kicinski >Reviewed-by: Vlad Buslov >Signed-off-by: Gal Pressman >Reviewed-by: Jakub Kicinski Reviewed-by: Jiri Pirko