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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38428C28CF6 for ; Wed, 1 Aug 2018 06:30:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E004720841 for ; Wed, 1 Aug 2018 06:30:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E004720841 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387479AbeHAIOT (ORCPT ); Wed, 1 Aug 2018 04:14:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:51030 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387419AbeHAIOT (ORCPT ); Wed, 1 Aug 2018 04:14:19 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 4EF48AEB9; Wed, 1 Aug 2018 06:30:14 +0000 (UTC) Subject: Re: [PATCH 1/3] fcoe: fix use-after-free in fcoe_ctlr_els_send To: Johannes Thumshirn , "Martin K . Petersen" Cc: Linux Kernel Mailinglist , Linux SCSI Mailinglist , ard References: <20180731134603.20089-1-jthumshirn@suse.de> <20180731134603.20089-2-jthumshirn@suse.de> From: Hannes Reinecke Message-ID: Date: Wed, 1 Aug 2018 08:30:13 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180731134603.20089-2-jthumshirn@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/31/2018 03:46 PM, Johannes Thumshirn wrote: > KASAN reports a use-after-free in fcoe_ctlr_els_send() when we're > sending a LOGO and have FIP debugging enabled. This is because we're > first freeing the skb and then printing the frame's DID. But the DID > is a member of the FC frame header which in turn is the skb's payload. > > Exchange the debug print and kfree_skb() calls so we're not touching > the freed data. > > Signed-off-by: Johannes Thumshirn > --- > drivers/scsi/fcoe/fcoe_ctlr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c > index ea23c8dffc25..ceb35ebbeb8f 100644 > --- a/drivers/scsi/fcoe/fcoe_ctlr.c > +++ b/drivers/scsi/fcoe/fcoe_ctlr.c > @@ -799,9 +799,9 @@ int fcoe_ctlr_els_send(struct fcoe_ctlr *fip, struct fc_lport *lport, > fip->send(fip, skb); > return -EINPROGRESS; > drop: > - kfree_skb(skb); > LIBFCOE_FIP_DBG(fip, "drop els_send op %u d_id %x\n", > op, ntoh24(fh->fh_d_id)); > + kfree_skb(skb); > return -EINVAL; > } > EXPORT_SYMBOL(fcoe_ctlr_els_send); > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)