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 456EEC433F5 for ; Tue, 19 Oct 2021 23:35:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26E53611B0 for ; Tue, 19 Oct 2021 23:35:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229987AbhJSXhm (ORCPT ); Tue, 19 Oct 2021 19:37:42 -0400 Received: from netrider.rowland.org ([192.131.102.5]:39695 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S229668AbhJSXhi (ORCPT ); Tue, 19 Oct 2021 19:37:38 -0400 Received: (qmail 1099285 invoked by uid 1000); 19 Oct 2021 19:35:24 -0400 Date: Tue, 19 Oct 2021 19:35:24 -0400 From: Alan Stern To: syzbot Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] UBSAN: array-index-out-of-bounds in ehci_hub_control Message-ID: <20211019233524.GA1099077@rowland.harvard.edu> References: <0000000000001611e605cebabab5@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0000000000001611e605cebabab5@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 19, 2021 at 01:44:24PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d999ade1cc86 Merge tag 'perf-tools-fixes-for-v5.15-2021-10.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17d85d34b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=b5d8cfd89abd92bf > dashboard link: https://syzkaller.appspot.com/bug?extid=9df2568864dedf79db36 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9df2568864dedf79db36@syzkaller.appspotmail.com > > ================================================================================ > UBSAN: array-index-out-of-bounds in drivers/usb/host/ehci-hub.c:754:39 > index 254 is out of range for type 'u32 [15]' > CPU: 0 PID: 11514 Comm: syz-executor.1 Not tainted 5.15.0-rc5-syzkaller #0 > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 This should already be fixed by https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git/commit/drivers/usb/host/ehci-hub.c?h=usb-next&id=846cbf98cbef20376b1a95fa3734c435543f3519 (although it can't be tested if there is no reproducer). That commit is scheduled to go into 5.16-rc1. This isn't really a bug, because the pointer doesn't get used in cases where the index is beyond the end of the array. Alan Stern