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 46A14C433F5 for ; Fri, 31 Dec 2021 17:33:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231481AbhLaRdC (ORCPT ); Fri, 31 Dec 2021 12:33:02 -0500 Received: from netrider.rowland.org ([192.131.102.5]:39931 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S229690AbhLaRdB (ORCPT ); Fri, 31 Dec 2021 12:33:01 -0500 Received: (qmail 1135077 invoked by uid 1000); 31 Dec 2021 12:33:00 -0500 Date: Fri, 31 Dec 2021 12:33:00 -0500 From: Alan Stern To: syzbot Cc: andreyknvl@google.com, dvyukov@google.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] KASAN: slab-out-of-bounds Write in usb_hcd_poll_rh_status (2) Message-ID: References: <00000000000065d16005d46a614b@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000000000065d16005d46a614b@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 30, 2021 at 09:24:09PM -0800, syzbot wrote: > Hello, > > syzbot has tested the proposed patch but the reproducer is still triggering an issue: > KASAN: slab-out-of-bounds Write in usb_hcd_poll_rh_status > > ================================================================== > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline] > BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x376/0x780 drivers/usb/core/hcd.c:774 > Write of size 2 at addr ffff8880127f7028 by task syz-executor029/4082 Still not enough information. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ eec4df26e24e Index: usb-devel/drivers/usb/core/devio.c =================================================================== --- usb-devel.orig/drivers/usb/core/devio.c +++ usb-devel/drivers/usb/core/devio.c @@ -109,7 +109,7 @@ struct async { u8 bulk_status; }; -static bool usbfs_snoop; +static bool usbfs_snoop = true; module_param(usbfs_snoop, bool, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(usbfs_snoop, "true to log all usbfs traffic"); Index: usb-devel/drivers/usb/core/hcd.c =================================================================== --- usb-devel.orig/drivers/usb/core/hcd.c +++ usb-devel/drivers/usb/core/hcd.c @@ -771,6 +771,8 @@ void usb_hcd_poll_rh_status(struct usb_h clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags); hcd->status_urb = NULL; urb->actual_length = length; + dev_info(hcd->self.controller, "poll_rh_status: len %d maxch %d tblen %d\n", + length, urb->dev->maxchild, urb->transfer_buffer_length); memcpy(urb->transfer_buffer, buffer, length); usb_hcd_unlink_urb_from_ep(hcd, urb); @@ -809,8 +811,10 @@ static int rh_queue_status (struct usb_h unsigned len = 1 + (urb->dev->maxchild / 8); spin_lock_irqsave (&hcd_root_hub_lock, flags); + dev_info(hcd->self.controller, "rh_queue_status: len %d maxch %d tblen %d\n", + len, urb->dev->maxchild, urb->transfer_buffer_length); if (hcd->status_urb || urb->transfer_buffer_length < len) { - dev_dbg (hcd->self.controller, "not queuing rh status urb\n"); + dev_info(hcd->self.controller, "not queuing rh status urb\n"); retval = -EINVAL; goto done; }