From mboxrd@z Thu Jan 1 00:00:00 1970 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 45309C54EBE for ; Thu, 12 Jan 2023 23:00:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232661AbjALXAX (ORCPT ); Thu, 12 Jan 2023 18:00:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232647AbjALXAW (ORCPT ); Thu, 12 Jan 2023 18:00:22 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99D5852C49 for ; Thu, 12 Jan 2023 15:00:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA92C62181 for ; Thu, 12 Jan 2023 23:00:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 07067C433D2; Thu, 12 Jan 2023 23:00:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673564420; bh=DLo5NJS1HgiJ9JJ9cVXzXouTi2SSZ8s+MnMpOc36hHA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=ByewWtaBIrwp2XbPJjlc1PkvGIpsD7KlCkqYkvUHhWLx4tFXe+MuQnxuvfIaOuZto WCXZVXIHuPbOid4EYt69QgRnp7EcIBDPbUY3dnXtZ/BkUoPI67CDqPCkibfeleDGxi ZDwCCmldBhC3Z3ltlUW8XM/MBBZ2WprpddS3iz7QFQ9cdIBHoJbmxCa5jvSInHhExe 13m5VxhE7sPDC7ix3zHOknxF6sFI5Upcj1Rcuqr6ygLYBxRDK9JTq8WbZ/MzbVCz1F cJuZeCmkKUyBPU67/ic0gF/Aj7bOVZ2G0TtVDhyv+m1EJPJpWcpVYnATBL5sCRWCW8 o4R5C7vWI8BOw== Date: Thu, 12 Jan 2023 17:00:18 -0600 From: Bjorn Helgaas To: "Alexey V. Vissarionov" Cc: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Bjorn Helgaas , Alex Williamson , Jesse Barnes , Matthew Wilcox , Yu Zhao , linux-pci@vger.kernel.org, lvc-project@linuxtesting.org Subject: Re: [PATCH] PCI/IOV: "virtfn4294967295\0" requires 17 bytes Message-ID: <20230112230018.GA1800747@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20221218122139.GA1182@altlinux.org> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Sun, Dec 18, 2022 at 03:21:39PM +0300, Alexey V. Vissarionov wrote: > On 2022-12-18 19:57:02 +0900, Krzysztof Wilczyński wrote: > > > Thank you for sending the patch over! However, if possible, > > can you send it as plain text without any multi-part MIME > > involved? > > ACK. > > > If possible, it would be nice to mention that this needed > > to make sure that there is enough space to correctly > > NULL-terminate the ID string. > > ACK. > > So, here goes the corrected text: > > Although unlikely, the 'id' value may be as big as 4294967295 > (uint32_max) and "virtfn4294967295\0" would require 17 bytes > instead of 16 to make sure that buffer has enough space to > properly NULL-terminate the ID string. > > Found by Linux Verification Center (linuxtesting.org) with SVACE. > > Fixes: dd7cc44d0 ("PCI: add SR-IOV API for Physical Function driver") > Signed-off-by: Alexey V. Vissarionov I collected this up and applied to pci/iov for v6.3 as below. I agree this is probably only a theoretical issue, but it's easier to spend a byte of stack space than to prove that we don't need to. Bjorn commit 58d4c63d0a27 ("PCI/IOV: Enlarge virtfn sysfs name buffer") parent 1b929c02afd3 Author: Alexey V. Vissarionov Date: Sun Dec 18 06:33:47 2022 +0300 PCI/IOV: Enlarge virtfn sysfs name buffer The sysfs link name "virtfn%u" constructed by pci_iov_sysfs_link() requires 17 bytes to contain the longest possible string. Increase VIRTFN_ID_LEN to accommodate that. Found by Linux Verification Center (linuxtesting.org) with SVACE. [bhelgaas: commit log, comment at #define] Fixes: dd7cc44d0 ("PCI: add SR-IOV API for Physical Function driver") Link: https://lore.kernel.org/r/20221218033347.23743-1-gremlin@altlinux.org Signed-off-by: Alexey V. Vissarionov Signed-off-by: Bjorn Helgaas diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 952217572113..b2e8322755c1 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -14,7 +14,7 @@ #include #include "pci.h" -#define VIRTFN_ID_LEN 16 +#define VIRTFN_ID_LEN 17 /* "virtfn%u\0" for 2^32 - 1 */ int pci_iov_virtfn_bus(struct pci_dev *dev, int vf_id) {