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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E56D4C5DF62 for ; Wed, 6 Nov 2019 08:39:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B475521882 for ; Wed, 6 Nov 2019 08:39:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="L6xaRbUA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731557AbfKFIjl (ORCPT ); Wed, 6 Nov 2019 03:39:41 -0500 Received: from mail-m974.mail.163.com ([123.126.97.4]:34842 "EHLO mail-m974.mail.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730212AbfKFIjj (ORCPT ); Wed, 6 Nov 2019 03:39:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=+JzU+esi7fl0h4YK8N PHkxPWloJ5wIl06K/wPnc/A2k=; b=L6xaRbUAJMTvsW09nge/+GKrTTCh43e6VO OSswfOX+OhhilUA4bHqozbqprvxu7fxm7mTUpPgGFyqG2f+1jzHNCdrDBuDY9ZXg aiCUKSIZSw9UTB4Jy1CcGxULHabKQP3rG/Ttoavt0yEO/D1/C4ALXy0Azd31k+py 373MrR5Mg= Received: from localhost.localdomain (unknown [202.112.113.212]) by smtp4 (Coremail) with SMTP id HNxpCgDHZtOBhsJdCHKDBQ--.289S3; Wed, 06 Nov 2019 16:38:35 +0800 (CST) From: Pan Bian To: Felipe Balbi , Greg Kroah-Hartman , Colin Ian King , Andy Shevchenko , Bjorn Helgaas , Chuhong Yuan Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] usb: gadget: pch_udc: fix use after free Date: Wed, 6 Nov 2019 16:38:23 +0800 Message-Id: <1573029503-18369-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: HNxpCgDHZtOBhsJdCHKDBQ--.289S3 X-Coremail-Antispam: 1Uf129KBjvdXoW7GrWUXr43Wr1UuF1kKF13twb_yoWfurcEk3 yjgFnrWryYq3Z8Kr4fJry3Ar4293ZYqan3uFnaqrZ3Z3y5Way5Xr18ZF9Y93y7uw47GF93 u3yqqFyYgF4S9jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU1jNt3UUUUU== X-Originating-IP: [202.112.113.212] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/1tbiDgtlclXluaTJ2AAAsu Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The next field of the DMA descriptor is written after releasing the descriptor, which may result in a use-after-free issue. Set the value of the field before it is released to fix the bug. Signed-off-by: Pan Bian --- drivers/usb/gadget/udc/pch_udc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c index 265dab2bbfac..c5b8ec908aab 100644 --- a/drivers/usb/gadget/udc/pch_udc.c +++ b/drivers/usb/gadget/udc/pch_udc.c @@ -1518,8 +1518,8 @@ static void pch_udc_free_dma_chain(struct pch_udc_dev *dev, /* do not free first desc., will be done by free for request */ td = phys_to_virt(addr); addr2 = (dma_addr_t)td->next; - dma_pool_free(dev->data_requests, td, addr); td->next = 0x00; + dma_pool_free(dev->data_requests, td, addr); addr = addr2; } req->chain_len = 1; -- 2.7.4