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 50331C433EF for ; Tue, 10 May 2022 13:29:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243282AbiEJNdH (ORCPT ); Tue, 10 May 2022 09:33:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243781AbiEJNcO (ORCPT ); Tue, 10 May 2022 09:32:14 -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 50B652CF2A5; Tue, 10 May 2022 06:22:08 -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 1151DB81DA6; Tue, 10 May 2022 13:22:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 677F6C385A6; Tue, 10 May 2022 13:22:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652188925; bh=tUBIoF9N6X0NiJbBCmDtbiWMfzpX2+Dhrt4Z/jqBemM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uFXi+tnl5mOV/uP2yeRlbQkNL3HvIK2c0ilH/W0uuB7c8bx5dqGEvdPyYGZrg7APc dVKe+zQuLdmXbuPrnXNaYYHlQyQXJ2dH/rMM+CVJmGAhOk9VZmhQiWD+bg7guBDqN/ 2ffXZMpmtb1BNmtvT+tVmOiatHuPHHrBTfjLu/Mw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Duoming Zhou , "David S. Miller" Subject: [PATCH 4.19 71/88] nfc: nfcmrvl: main: reorder destructive operations in nfcmrvl_nci_unregister_dev to avoid bugs Date: Tue, 10 May 2022 15:07:56 +0200 Message-Id: <20220510130735.795322640@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220510130733.735278074@linuxfoundation.org> References: <20220510130733.735278074@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Duoming Zhou commit d270453a0d9ec10bb8a802a142fb1b3601a83098 upstream. There are destructive operations such as nfcmrvl_fw_dnld_abort and gpio_free in nfcmrvl_nci_unregister_dev. The resources such as firmware, gpio and so on could be destructed while the upper layer functions such as nfcmrvl_fw_dnld_start and nfcmrvl_nci_recv_frame is executing, which leads to double-free, use-after-free and null-ptr-deref bugs. There are three situations that could lead to double-free bugs. The first situation is shown below: (Thread 1) | (Thread 2) nfcmrvl_fw_dnld_start | ... | nfcmrvl_nci_unregister_dev release_firmware() | nfcmrvl_fw_dnld_abort kfree(fw) //(1) | fw_dnld_over | release_firmware ... | kfree(fw) //(2) | ... The second situation is shown below: (Thread 1) | (Thread 2) nfcmrvl_fw_dnld_start | ... | mod_timer | (wait a time) | fw_dnld_timeout | nfcmrvl_nci_unregister_dev fw_dnld_over | nfcmrvl_fw_dnld_abort release_firmware | fw_dnld_over kfree(fw) //(1) | release_firmware ... | kfree(fw) //(2) The third situation is shown below: (Thread 1) | (Thread 2) nfcmrvl_nci_recv_frame | if(..->fw_download_in_progress)| nfcmrvl_fw_dnld_recv_frame | queue_work | | fw_dnld_rx_work | nfcmrvl_nci_unregister_dev fw_dnld_over | nfcmrvl_fw_dnld_abort release_firmware | fw_dnld_over kfree(fw) //(1) | release_firmware | kfree(fw) //(2) The firmware struct is deallocated in position (1) and deallocated in position (2) again. The crash trace triggered by POC is like below: BUG: KASAN: double-free or invalid-free in fw_dnld_over Call Trace: kfree fw_dnld_over nfcmrvl_nci_unregister_dev nci_uart_tty_close tty_ldisc_kill tty_ldisc_hangup __tty_hangup.part.0 tty_release ... What's more, there are also use-after-free and null-ptr-deref bugs in nfcmrvl_fw_dnld_start. If we deallocate firmware struct, gpio or set null to the members of priv->fw_dnld in nfcmrvl_nci_unregister_dev, then, we dereference firmware, gpio or the members of priv->fw_dnld in nfcmrvl_fw_dnld_start, the UAF or NPD bugs will happen. This patch reorders destructive operations after nci_unregister_device in order to synchronize between cleanup routine and firmware download routine. The nci_unregister_device is well synchronized. If the device is detaching, the firmware download routine will goto error. If firmware download routine is executing, nci_unregister_device will wait until firmware download routine is finished. Fixes: 3194c6870158 ("NFC: nfcmrvl: add firmware download support") Signed-off-by: Duoming Zhou Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/nfc/nfcmrvl/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/nfc/nfcmrvl/main.c +++ b/drivers/nfc/nfcmrvl/main.c @@ -194,6 +194,7 @@ void nfcmrvl_nci_unregister_dev(struct n { struct nci_dev *ndev = priv->ndev; + nci_unregister_device(ndev); if (priv->ndev->nfc_dev->fw_download_in_progress) nfcmrvl_fw_dnld_abort(priv); @@ -202,7 +203,6 @@ void nfcmrvl_nci_unregister_dev(struct n if (gpio_is_valid(priv->config.reset_n_io)) gpio_free(priv->config.reset_n_io); - nci_unregister_device(ndev); nci_free_device(ndev); kfree(priv); }