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 25E38C433F5 for ; Fri, 30 Sep 2022 08:53:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231260AbiI3Ixj (ORCPT ); Fri, 30 Sep 2022 04:53:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230480AbiI3Ixh (ORCPT ); Fri, 30 Sep 2022 04:53:37 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8766A166F36 for ; Fri, 30 Sep 2022 01:53:36 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id D4BAACE2474 for ; Fri, 30 Sep 2022 08:53:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D1DADC433C1; Fri, 30 Sep 2022 08:53:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1664528011; bh=UD5PXLj2rv1kSGjBOp+GMtpGLrvoukpy022/UGx3wsg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0qEo2s4u3lUhQFICdNtAh93hpb6oAazz6tcan79PuFdfH6C6A4tegsOXKQ+ZHvCmy JwLnJoxZuBaxh55EKjSpx48PMhJrJZhioOg4Am7P00kkkpJIOICZ6dTY7RE3pjqFlG Xmb0umeIFlTR0lp2vBBTJl0Yh65+hpIC/XaP+rUo= Date: Fri, 30 Sep 2022 10:53:28 +0200 From: Greg KH To: bugzilla-daemon@kernel.org Cc: linux-usb@vger.kernel.org Subject: Re: [Bug 216543] New: kernel NULL pointer dereference usb_hcd_alloc_bandwidth Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Sep 29, 2022 at 06:53:46PM +0000, bugzilla-daemon@kernel.org wrote: > With a flaky USB 3.0 cable (3m extension + 2m cable + 90 degree adapter) and > Logitech BRIO webcam I got exactly the same null pointer dereference twice > already. That's really an unstable and unsupported system, sorry. If you fix your cable it should work properly, right? > Here are two instances (from different boots): > [64977.148098] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [64977.148101] #PF: supervisor read access in kernel mode > [64977.148102] #PF: error_code(0x0000) - not-present page > [64977.148103] PGD 101370067 P4D 101370067 PUD 0 > [64977.148105] Oops: 0000 [#1] SMP NOPTI > [64977.148107] CPU: 14 PID: 27951 Comm: VideoCapture Not tainted > 5.19.10-xanmod1-x64v2 #0~20220920.git017c598 What about any kernel log messages from right before this crashed? There should be some disconnect or other USB messages, right? Specifics here would be good to see. > [64977.148109] Hardware name: Gigabyte Technology Co., Ltd. B550 VISION D/B550 > VISION D, BIOS F15d 07/20/2022 > [64977.148109] RIP: 0010:usb_ifnum_to_if+0x34/0x60 > [64977.148113] Code: 74 33 0f b6 4a 04 84 c9 74 33 83 e9 01 48 8d 82 98 00 00 > 00 48 8d bc ca a0 00 00 00 eb 09 48 83 c0 08 48 39 f8 74 16 48 8b 10 <48> 8b 0a > 0f b6 49 02 39 f1 75 e9 48 89 d0 c3 cc cc cc cc 31 d2 48 > [64977.148114] RSP: 0018:ffffb20951407bb0 EFLAGS: 00010202 > [64977.148115] RAX: ffff8cfbbc618098 RBX: ffff8ceb844cc800 RCX: > 0000000000000004 > [64977.148116] RDX: 0000000000000000 RSI: 0000000000000001 RDI: > ffff8cfbbc6180c0 > [64977.148117] RBP: 0000000000000000 R08: 0000000080000000 R09: > ffffffff8f590de8 > [64977.148117] R10: 0000000000000001 R11: 0000000000000001 R12: > ffff8cf67c70f398 > [64977.148118] R13: 0000000000000000 R14: ffff8cf67c70f208 R15: > ffff8ceb8123c000 > [64977.148119] FS: 00007f5f51379640(0000) GS:ffff8d0a3ed80000(0000) > knlGS:0000000000000000 > [64977.148120] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [64977.148120] CR2: 0000000000000000 CR3: 000000023b842000 CR4: > 0000000000750ee0 > [64977.148121] PKRU: 55555554 > [64977.148122] Call Trace: > [64977.148123] > [64977.148124] usb_hcd_alloc_bandwidth+0x241/0x360 > [64977.148127] usb_set_interface+0x11d/0x340 > [64977.148130] uvc_video_start_transfer+0x17b/0x4b0 [uvcvideo] This isn't good, we shouldn't crash when a device is removed, but this might be an issue with some reference counting. More log messages might help out here. thanks, greg k-h