From patchwork Tue Apr 26 08:21:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 566737 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 A8113C433EF for ; Tue, 26 Apr 2022 08:23:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344672AbiDZI0k (ORCPT ); Tue, 26 Apr 2022 04:26:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344650AbiDZI0k (ORCPT ); Tue, 26 Apr 2022 04:26:40 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADF9C39BBF; Tue, 26 Apr 2022 01:23:00 -0700 (PDT) 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 ams.source.kernel.org (Postfix) with ESMTPS id 1FDC9B81CF9; Tue, 26 Apr 2022 08:22:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8861FC385A4; Tue, 26 Apr 2022 08:22:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650961377; bh=Bx27VgkRiumPQICKNZ2fk+CxzxjYO6ZrkulKOdcWCRw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hZ5WR06o1XwHfxemSDLQE2tgyXAtYLEHSjqI6LcHWKCuHfeO+rkN9GU1AuD6MAjY8 7uU24jvMkWITENSPIFLHfvtLYT6FB/g/J9u6nyAB81vsRb+n3aR+0wZrIbxflO+aLr AEDLySeNtSyUbhHHkh/Cm6tqnGBQ9oiBPv29XJsU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaomeng Tong , Vinod Koul Subject: [PATCH 4.9 16/24] dma: at_xdmac: fix a missing check on list iterator Date: Tue, 26 Apr 2022 10:21:10 +0200 Message-Id: <20220426081731.852434263@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081731.370823950@linuxfoundation.org> References: <20220426081731.370823950@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiaomeng Tong commit 206680c4e46b62fd8909385e0874a36952595b85 upstream. The bug is here: __func__, desc, &desc->tx_dma_desc.phys, ret, cookie, residue); The list iterator 'desc' will point to a bogus position containing HEAD if the list is empty or no element is found. To avoid dev_dbg() prints a invalid address, use a new variable 'iter' as the list iterator, while use the origin variable 'desc' as a dedicated pointer to point to the found element. Cc: stable@vger.kernel.org Fixes: 82e2424635f4c ("dmaengine: xdmac: fix print warning on dma_addr_t variable") Signed-off-by: Xiaomeng Tong Link: https://lore.kernel.org/r/20220327061154.4867-1-xiam0nd.tong@gmail.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/at_xdmac.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1392,7 +1392,7 @@ at_xdmac_tx_status(struct dma_chan *chan { struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); struct at_xdmac *atxdmac = to_at_xdmac(atchan->chan.device); - struct at_xdmac_desc *desc, *_desc; + struct at_xdmac_desc *desc, *_desc, *iter; struct list_head *descs_list; enum dma_status ret; int residue, retry; @@ -1507,11 +1507,13 @@ at_xdmac_tx_status(struct dma_chan *chan * microblock. */ descs_list = &desc->descs_list; - list_for_each_entry_safe(desc, _desc, descs_list, desc_node) { - dwidth = at_xdmac_get_dwidth(desc->lld.mbr_cfg); - residue -= (desc->lld.mbr_ubc & 0xffffff) << dwidth; - if ((desc->lld.mbr_nda & 0xfffffffc) == cur_nda) + list_for_each_entry_safe(iter, _desc, descs_list, desc_node) { + dwidth = at_xdmac_get_dwidth(iter->lld.mbr_cfg); + residue -= (iter->lld.mbr_ubc & 0xffffff) << dwidth; + if ((iter->lld.mbr_nda & 0xfffffffc) == cur_nda) { + desc = iter; break; + } } residue += cur_ubc << dwidth;