From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030258AbXEHONs (ORCPT ); Tue, 8 May 2007 10:13:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S967449AbXEHONs (ORCPT ); Tue, 8 May 2007 10:13:48 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:53205 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967285AbXEHONr (ORCPT ); Tue, 8 May 2007 10:13:47 -0400 Date: Tue, 8 May 2007 07:14:53 -0700 From: Greg KH To: Dan Kruchinin Cc: linux-kernel@vger.kernel.org, Andrew Morton , linux-usb-devel@lists.sourceforge.net Subject: Re: [PATCH -mm] drivers/usb/core/config.c: kzalloc(0,..) Message-ID: <20070508141453.GA12771@kroah.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.15 (2007-04-06) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 08, 2007 at 07:03:08AM +0400, Dan Kruchinin wrote: > The following patch fixes such SLUB report(when someone tries to > allocate 0 bytes): > -- > May 8 00:19:15 midgard kernel: [ 21.933467] BUG: at > include/linux/slub_def.h:88 kmalloc_index() > May 8 00:19:15 midgard kernel: [ 21.933470] > [show_registers+410/736] show_trace_log_lvl+0x1a/0x30 > May 8 00:19:15 midgard kernel: [ 21.933478] > [print_trace_warning_symbol+50/64] show_trace+0x12/0x20 > May 8 00:19:15 midgard kernel: [ 21.933482] [fixup_irqs+38/192] > dump_stack+0x16/0x20 > May 8 00:19:15 midgard kernel: [ 21.933485] [do_lookup+195/400] > get_slab+0x213/0x230 > May 8 00:19:15 midgard kernel: [ 21.933489] [do_lookup+309/400] > __kmalloc_track_caller+0x15/0x40 > May 8 00:19:15 midgard kernel: [ 21.933493] [__vunmap+25/240] > __kzalloc+0x19/0x50 > May 8 00:19:15 midgard kernel: [ 21.933498] [] > usb_parse_configuration+0x85e/0xe70 [usbcore] > May 8 00:19:15 midgard kernel: [ 21.933520] [] > usb_get_configuration+0x12b/0x450 [usbcore] > May 8 00:19:15 midgard kernel: [ 21.933535] [] > usb_new_device+0x17/0x1c0 [usbcore] > May 8 00:19:15 midgard kernel: [ 21.933550] [] > hub_thread+0x79a/0xfd0 [usbcore] > May 8 00:19:15 midgard kernel: [ 21.933564] > [run_posix_cpu_timers+1218/2064] kthread+0x42/0x70 > May 8 00:19:15 midgard kernel: [ 21.933569] [math_error+87/240] > kernel_thread_helper+0x7/0x10 > May 8 00:19:15 midgard kernel: [ 21.933572] ======================= > -- > > The problem was in drivers/usb/core/config.c in function > usb_parse_interface: > --- > num_ep = num_ep_orig = alt->desc.bNumEndpoints; > ... > len = sizeof(struct usb_host_endpoint) * num_ep; > alt->endpoint = kzalloc(len, GFP_KERNEL); > --- > > num_ep can be 0, as it was in my case, so following patch makes this > situation more obvious > and clear. Well, the whitespace was damaged, but the idea looks sane. Care to respin this? However, what kind of device do you have that you have no endpoints for an interface? Why have the interface then? thanks, greg k-h