From nobody Sun May 10 15:44:35 2026 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 D0F75C433EF for ; Fri, 29 Apr 2022 12:46:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359482AbiD2Mtz (ORCPT ); Fri, 29 Apr 2022 08:49:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359428AbiD2Mtk (ORCPT ); Fri, 29 Apr 2022 08:49:40 -0400 Received: from zju.edu.cn (mail.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BEC3C97292; Fri, 29 Apr 2022 05:46:20 -0700 (PDT) Received: from ubuntu.localdomain (unknown [10.15.192.164]) by mail-app3 (Coremail) with SMTP id cC_KCgCnb3kJ3mtiQdNCAw--.63343S3; Fri, 29 Apr 2022 20:46:09 +0800 (CST) From: Duoming Zhou To: krzysztof.kozlowski@linaro.org, kuba@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, netdev@vger.kernel.org, alexander.deucher@amd.com, broonie@kernel.org, linma@zju.edu.cn, Duoming Zhou Subject: [PATCH net v6 1/2] nfc: replace improper check device_is_registered() in netlink related functions Date: Fri, 29 Apr 2022 20:45:50 +0800 Message-Id: <13fc7da008ae0f18afed52059529142cfd640821.1651235400.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-CM-TRANSID: cC_KCgCnb3kJ3mtiQdNCAw--.63343S3 X-Coremail-Antispam: 1UD129KBjvJXoWxuF1fZr17Jw4fKF1kKr4Durg_yoWrtr4Upa 4rKasakr4xWr1UWr4qqw4UCFy09r10qw4rury8GFy7KrZ3Xa4rtF1ftryxAa48t39xAayY qrWUJw48Wr4ruFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvG1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2 z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcV Aq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxAIw28I cxkI7VAKI48JMxAIw28IcVCjz48v1sIEY20_GFWkJr1UJwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvE x4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa 73UjIFyTuYvjfUoOJ5UUUUU X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAgAPAVZdtZdzvwAGsv Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The device_is_registered() in nfc core is used to check whether nfc device is registered in netlink related functions such as nfc_fw_download(), nfc_dev_up() and so on. Although device_is_registered() is protected by device_lock, there is still a race condition between device_del() and device_is_registered(). The root cause is that kobject_del() in device_del() is not protected by device_lock. (cleanup task) | (netlink task) | nfc_unregister_device | nfc_fw_download device_del | device_lock ... | if (!device_is_registered)//(1) kobject_del//(2) | ... ... | device_unlock The device_is_registered() returns the value of state_in_sysfs and the state_in_sysfs is set to zero in kobject_del(). If we pass check in position (1), then set zero in position (2). As a result, the check in position (1) is useless. This patch uses bool variable instead of device_is_registered() to judge whether the nfc device is registered, which is well synchronized. Fixes: 3e256b8f8dfa ("NFC: add nfc subsystem core") Signed-off-by: Duoming Zhou --- Changes in v6: - Replace dev_register flag in v5 to shutting_down flag. net/nfc/core.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-) diff --git a/net/nfc/core.c b/net/nfc/core.c index dc7a2404efd..5b286e1e0a6 100644 --- a/net/nfc/core.c +++ b/net/nfc/core.c @@ -38,7 +38,7 @@ int nfc_fw_download(struct nfc_dev *dev, const char *firm= ware_name) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -94,7 +94,7 @@ int nfc_dev_up(struct nfc_dev *dev) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -142,7 +142,7 @@ int nfc_dev_down(struct nfc_dev *dev) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -207,7 +207,7 @@ int nfc_start_poll(struct nfc_dev *dev, u32 im_protocol= s, u32 tm_protocols) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -246,7 +246,7 @@ int nfc_stop_poll(struct nfc_dev *dev) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -291,7 +291,7 @@ int nfc_dep_link_up(struct nfc_dev *dev, int target_ind= ex, u8 comm_mode) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -335,7 +335,7 @@ int nfc_dep_link_down(struct nfc_dev *dev) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -401,7 +401,7 @@ int nfc_activate_target(struct nfc_dev *dev, u32 target= _idx, u32 protocol) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -448,7 +448,7 @@ int nfc_deactivate_target(struct nfc_dev *dev, u32 targ= et_idx, u8 mode) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -495,7 +495,7 @@ int nfc_data_exchange(struct nfc_dev *dev, u32 target_i= dx, struct sk_buff *skb, =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; kfree_skb(skb); goto error; @@ -552,7 +552,7 @@ int nfc_enable_se(struct nfc_dev *dev, u32 se_idx) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -601,7 +601,7 @@ int nfc_disable_se(struct nfc_dev *dev, u32 se_idx) =20 device_lock(&dev->dev); =20 - if (!device_is_registered(&dev->dev)) { + if (dev->shutting_down) { rc =3D -ENODEV; goto error; } @@ -1134,6 +1134,7 @@ int nfc_register_device(struct nfc_dev *dev) dev->rfkill =3D NULL; } } + dev->shutting_down =3D false; device_unlock(&dev->dev); =20 rc =3D nfc_genl_device_added(dev); @@ -1166,12 +1167,10 @@ void nfc_unregister_device(struct nfc_dev *dev) rfkill_unregister(dev->rfkill); rfkill_destroy(dev->rfkill); } + dev->shutting_down =3D true; device_unlock(&dev->dev); =20 if (dev->ops->check_presence) { - device_lock(&dev->dev); - dev->shutting_down =3D true; - device_unlock(&dev->dev); del_timer_sync(&dev->check_pres_timer); cancel_work_sync(&dev->check_pres_work); } --=20 2.17.1 From nobody Sun May 10 15:44:35 2026 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 07827C433FE for ; Fri, 29 Apr 2022 12:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359452AbiD2Mtr (ORCPT ); Fri, 29 Apr 2022 08:49:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359432AbiD2Mtk (ORCPT ); Fri, 29 Apr 2022 08:49:40 -0400 Received: from zju.edu.cn (spam.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 92D43972BA; Fri, 29 Apr 2022 05:46:21 -0700 (PDT) Received: from ubuntu.localdomain (unknown [10.15.192.164]) by mail-app3 (Coremail) with SMTP id cC_KCgCnb3kJ3mtiQdNCAw--.63343S4; Fri, 29 Apr 2022 20:46:11 +0800 (CST) From: Duoming Zhou To: krzysztof.kozlowski@linaro.org, kuba@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, netdev@vger.kernel.org, alexander.deucher@amd.com, broonie@kernel.org, linma@zju.edu.cn, Duoming Zhou Subject: [PATCH net v6 2/2] nfc: nfcmrvl: main: reorder destructive operations in nfcmrvl_nci_unregister_dev to avoid bugs Date: Fri, 29 Apr 2022 20:45:51 +0800 Message-Id: X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-CM-TRANSID: cC_KCgCnb3kJ3mtiQdNCAw--.63343S4 X-Coremail-Antispam: 1UD129KBjvJXoWxAFW5Xw43WrWUAw17ZFy7Wrg_yoW5tF47pF 4rGFy5AF1DKr4FgFWDtF4DAFyruws3CFW5CrW3GryfZrs8tFW8tr1qy3yUXrsrXr4UJayY g3W3A348WF4qyFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvG1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2 z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcV Aq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxAIw28I cxkI7VAKI48JMxAIw28IcVCjz48v1sIEY20_GFWkJr1UJwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvE x4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa 73UjIFyTuYvjfUoOJ5UUUUU X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAgAPAVZdtZdzvwAIsh Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 --- Changes in v6: - Make commit messages more clearer. 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 =3D priv->ndev; =20 + nci_unregister_device(ndev); if (priv->ndev->nfc_dev->fw_download_in_progress) nfcmrvl_fw_dnld_abort(priv); =20 @@ -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); =20 - nci_unregister_device(ndev); nci_free_device(ndev); kfree(priv); } --=20 2.17.1