From patchwork Mon Mar 1 16:10:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 389932 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 4072AC4360C for ; Mon, 1 Mar 2021 17:35:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1FE6564F42 for ; Mon, 1 Mar 2021 17:35:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238380AbhCARdG (ORCPT ); Mon, 1 Mar 2021 12:33:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:49370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238421AbhCAR1B (ORCPT ); Mon, 1 Mar 2021 12:27:01 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 59D766508D; Mon, 1 Mar 2021 16:51:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614617471; bh=PKy+BTdVpY5bdXj1vnnfybhkRjj+pobNfcSHDw8vm/E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PLlD4xB1PT62lPpVROcW+CccvvxMLodQD86PWoOA9UPFJ3Hrl2hC8LKdzpU8SsAz6 nr49MCHqs91CTpMRbOL0fLNACZ9VoBEeqWqmEZxldeyyZCPx8SSoMb9WVZYqqB7lBl 9qFOkDQF/TwVrNXjSEkiMuXSmNmVeZITktUmn3s8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dinghao Liu , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.4 085/340] media: em28xx: Fix use-after-free in em28xx_alloc_urbs Date: Mon, 1 Mar 2021 17:10:29 +0100 Message-Id: <20210301161052.509353711@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161048.294656001@linuxfoundation.org> References: <20210301161048.294656001@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dinghao Liu [ Upstream commit a26efd1961a18b91ae4cd2e433adbcf865b40fa3 ] When kzalloc() fails, em28xx_uninit_usb_xfer() will free usb_bufs->buf and set it to NULL. Thus the later access to usb_bufs->buf[i] will lead to null pointer dereference. Also the kfree(usb_bufs->buf) after that is redundant. Fixes: d571b592c6206 ("media: em28xx: don't use coherent buffer for DMA transfers") Signed-off-by: Dinghao Liu Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/em28xx/em28xx-core.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c index e6088b5d1b805..3daa64bb1e1d9 100644 --- a/drivers/media/usb/em28xx/em28xx-core.c +++ b/drivers/media/usb/em28xx/em28xx-core.c @@ -956,14 +956,10 @@ int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk, usb_bufs->buf[i] = kzalloc(sb_size, GFP_KERNEL); if (!usb_bufs->buf[i]) { - em28xx_uninit_usb_xfer(dev, mode); - for (i--; i >= 0; i--) kfree(usb_bufs->buf[i]); - kfree(usb_bufs->buf); - usb_bufs->buf = NULL; - + em28xx_uninit_usb_xfer(dev, mode); return -ENOMEM; }