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 98EAFC433EF for ; Fri, 29 Apr 2022 01:15:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353853AbiD2BS3 (ORCPT ); Thu, 28 Apr 2022 21:18:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345538AbiD2BSX (ORCPT ); Thu, 28 Apr 2022 21:18:23 -0400 Received: from zju.edu.cn (mail.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4632F5F5C; Thu, 28 Apr 2022 18:15:05 -0700 (PDT) Received: from ubuntu.localdomain (unknown [10.15.192.164]) by mail-app4 (Coremail) with SMTP id cS_KCgAnDkX6O2tidX4EAg--.28704S4; Fri, 29 Apr 2022 09:14:54 +0800 (CST) From: Duoming Zhou To: linux-kernel@vger.kernel.org, kuba@kernel.org, krzysztof.kozlowski@linaro.org, gregkh@linuxfoundation.org Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, alexander.deucher@amd.com, akpm@linux-foundation.org, broonie@kernel.org, netdev@vger.kernel.org, linma@zju.edu.cn, Duoming Zhou Subject: [PATCH net v5 2/2] nfc: nfcmrvl: main: reorder destructive operations in nfcmrvl_nci_unregister_dev to avoid bugs Date: Fri, 29 Apr 2022 09:14:33 +0800 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-CM-TRANSID: cS_KCgAnDkX6O2tidX4EAg--.28704S4 X-Coremail-Antispam: 1UD129KBjvJXoWxAFW5Xw43WrWUAw17ZFy7Wrg_yoWrZrWUpF 4FgFy5Cr1DKr4FqF45tF4qgFyruFZ3GFW5CryfJryfZws0yFWvyw1qyay5ZFnruryUJFWY ka43A348GF4vyFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvm1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJr0_GcWl84ACjcxK6I8E 87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c 8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_ Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwI xGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IY c2Ij64vIr41l42xK82IY6x8ErcxFaVAv8VW8uw4UJr1UMxC20s026xCaFVCjc4AY6r1j6r 4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF 67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2I x0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2 z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnU UI43ZEXa7VUbXdbUUUUUU== X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAgIOAVZdtZdEXAA7sF Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: [ 122.640457] BUG: KASAN: double-free or invalid-free in fw_dnld_over+0x28/0xf0 [ 122.640457] Call Trace: [ 122.640457] [ 122.640457] kfree+0xb0/0x330 [ 122.640457] fw_dnld_over+0x28/0xf0 [ 122.640457] nfcmrvl_nci_unregister_dev+0x61/0x70 [ 122.640457] nci_uart_tty_close+0x87/0xd0 [ 122.640457] tty_ldisc_kill+0x3e/0x80 [ 122.640457] tty_ldisc_hangup+0x1b2/0x2c0 [ 122.640457] __tty_hangup.part.0+0x316/0x520 [ 122.640457] tty_release+0x200/0x670 [ 122.640457] __fput+0x110/0x410 [ 122.640457] task_work_run+0x86/0xd0 [ 122.640457] exit_to_user_mode_prepare+0x1aa/0x1b0 [ 122.640457] syscall_exit_to_user_mode+0x19/0x50 [ 122.640457] do_syscall_64+0x48/0x90 [ 122.640457] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 122.640457] RIP: 0033:0x7f68433f6beb 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 and uses bool variable in nfc_dev to synchronize between cleanup routine and firmware download routine. The process is shown below. (Thread 1) | (Thread 2) nfcmrvl_nci_unregister_dev | nci_unregister_device | nfc_unregister_device | nfc_fw_download device_lock() | ... | dev->dev_register = false; | ... device_unlock() | ... | device_lock() (destructive operations) | if(!dev->dev_register) | goto error; | error: | device_unlock() If the device is detaching, the download function will goto error. If the download function is executing, nci_unregister_device will wait until download function is finished. Fixes: 3194c6870158 ("NFC: nfcmrvl: add firmware download support") Signed-off-by: Duoming Zhou --- Changes in v5: - Use bool variable added in patch 1/2 to synchronize. drivers/nfc/nfcmrvl/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c index 2fcf545012b..1a5284de434 100644 --- a/drivers/nfc/nfcmrvl/main.c +++ b/drivers/nfc/nfcmrvl/main.c @@ -183,6 +183,7 @@ void nfcmrvl_nci_unregister_dev(struct nfcmrvl_private *priv) { struct nci_dev *ndev = priv->ndev; + nci_unregister_device(ndev); if (priv->ndev->nfc_dev->fw_download_in_progress) nfcmrvl_fw_dnld_abort(priv); @@ -191,7 +192,6 @@ void nfcmrvl_nci_unregister_dev(struct nfcmrvl_private *priv) 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); } -- 2.17.1