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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 847CBC433F5 for ; Wed, 10 Nov 2021 18:54:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BCAD61178 for ; Wed, 10 Nov 2021 18:54:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233350AbhKJS44 (ORCPT ); Wed, 10 Nov 2021 13:56:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:54534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233560AbhKJSyy (ORCPT ); Wed, 10 Nov 2021 13:54:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C523561267; Wed, 10 Nov 2021 18:49:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636570151; bh=r4EKlAP/qT+/vmwpqdDkK+ExL9hnK0ixt3w74HlTU88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cb1sjnAe8ujhYraIKWD3Y5h9EIpYwbVOVYOV/1EgCvVLTPSjz7tQypQF9SfhwU0YF ogcizPZ/0u3jyNgzI5txDVlEsgFgKAaRDKWCDWI1dKyAJzJGcCYtXxddqPpteNX6Uw +jDwWgf9URpmpu3CR3xGMhN4gBTK3D0jQdlkpLqQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Skripkin , syzbot+c55162be492189fb4f51@syzkaller.appspotmail.com Subject: [PATCH 5.14 14/24] staging: rtl8712: fix use-after-free in rtl8712_dl_fw Date: Wed, 10 Nov 2021 19:44:06 +0100 Message-Id: <20211110182003.788283916@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211110182003.342919058@linuxfoundation.org> References: <20211110182003.342919058@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: linux-kernel@vger.kernel.org From: Pavel Skripkin commit c052cc1a069c3e575619cf64ec427eb41176ca70 upstream. Syzbot reported use-after-free in rtl8712_dl_fw(). The problem was in race condition between r871xu_dev_remove() ->ndo_open() callback. It's easy to see from crash log, that driver accesses released firmware in ->ndo_open() callback. It may happen, since driver was releasing firmware _before_ unregistering netdev. Fix it by moving unregister_netdev() before cleaning up resources. Call Trace: ... rtl871x_open_fw drivers/staging/rtl8712/hal_init.c:83 [inline] rtl8712_dl_fw+0xd95/0xe10 drivers/staging/rtl8712/hal_init.c:170 rtl8712_hal_init drivers/staging/rtl8712/hal_init.c:330 [inline] rtl871x_hal_init+0xae/0x180 drivers/staging/rtl8712/hal_init.c:394 netdev_open+0xe6/0x6c0 drivers/staging/rtl8712/os_intfs.c:380 __dev_open+0x2bc/0x4d0 net/core/dev.c:1484 Freed by task 1306: ... release_firmware+0x1b/0x30 drivers/base/firmware_loader/main.c:1053 r871xu_dev_remove+0xcc/0x2c0 drivers/staging/rtl8712/usb_intf.c:599 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458 Fixes: 8c213fa59199 ("staging: r8712u: Use asynchronous firmware loading") Cc: stable Reported-and-tested-by: syzbot+c55162be492189fb4f51@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Link: https://lore.kernel.org/r/20211019211718.26354-1-paskripkin@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8712/usb_intf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/staging/rtl8712/usb_intf.c +++ b/drivers/staging/rtl8712/usb_intf.c @@ -595,12 +595,12 @@ static void r871xu_dev_remove(struct usb /* never exit with a firmware callback pending */ wait_for_completion(&padapter->rtl8712_fw_ready); + if (pnetdev->reg_state != NETREG_UNINITIALIZED) + unregister_netdev(pnetdev); /* will call netdev_close() */ usb_set_intfdata(pusb_intf, NULL); release_firmware(padapter->fw); if (drvpriv.drv_registered) padapter->surprise_removed = true; - if (pnetdev->reg_state != NETREG_UNINITIALIZED) - unregister_netdev(pnetdev); /* will call netdev_close() */ r8712_flush_rwctrl_works(padapter); r8712_flush_led_works(padapter); udelay(1);