Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753337Ab3CFHlN (ORCPT ); Wed, 6 Mar 2013 02:41:13 -0500 Received: from smtp.nue.novell.com ([195.135.221.5]:51273 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751004Ab3CFHlM (ORCPT ); Wed, 6 Mar 2013 02:41:12 -0500 Subject: Re: [PATCH] efivarfs: fix abnormal GUID in variable name by using strcpy to replace null with dash From: joeyli To: Matt Fleming Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Schroeder , Josh Boyer , Peter Jones , Matthew Garrett , Frederic Crozat In-Reply-To: <1362555258.23932.573.camel@linux-s257.site> References: <1362108018-13117-1-git-send-email-jlee@suse.com> <1362151068.2842.440.camel@mfleming-mobl1.ger.corp.intel.com> <1362155493.2842.446.camel@mfleming-mobl1.ger.corp.intel.com> <1362181299.23932.168.camel@linux-s257.site> <1362555258.23932.573.camel@linux-s257.site> Content-Type: text/plain; charset="UTF-8" Date: Wed, 06 Mar 2013 15:39:49 +0800 Message-ID: <1362555589.23932.582.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2601 Lines: 76 於 三，2013-03-06 於 15:34 +0800，joeyli 提到： > Hi Matt, > > 於 六，2013-03-02 於 07:41 +0800，joeyli 提到： > > 於 五，2013-03-01 於 16:31 +0000，Matt Fleming 提到： > > > On Fri, 2013-03-01 at 15:17 +0000, Matt Fleming wrote: > > > > On Fri, 2013-03-01 at 11:20 +0800, Lee, Chun-Yi wrote: > > > > > From: Michael Schroeder > > > > > > > > > > On HP z220 system (firmware version 1.54), some EFI variables > are incorrectly > > > > > named : > > > > > > > > > > ls -d /sys/firmware/efi/vars/*8be4d* | grep -v -- -8be returns > > > > > > /sys/firmware/efi/vars/dbxDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > > > > > > /sys/firmware/efi/vars/KEKDefault-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > > > > > > /sys/firmware/efi/vars/SecureBoot-pport8be4df61-93ca-11d2-aa0d-00e098032b8c > > > > > > /sys/firmware/efi/vars/SetupMode-Information8be4df61-93ca-11d2-aa0d-00e098032b8c > > > > > > > > > > That causes by the following statement in > efivar_create_sysfs_entry function: > > > > > > > > > > *(short_name + strlen(short_name)) = '-'; > > > > > efi_guid_unparse(vendor_guid, short_name + > strlen(short_name)); > > > > > > > > > > The trailing \0 is overwritten with '-', but the next char > doesn't seem to be a \0 > > > > > as well for HP. So, the second strlen return the point of next > '\0', causes there > > > > > have garbage string attached before GUID. > > > > > > > > > > Tested on On HP z220. > > > > > > > > What's more likely happening here is that GetNextVariable() is > broken on > > > > this HP firmware and variable_name_size is too big for the given > > > > variable in variable_name. We've seen other reports of similar > bugs, > > > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=47631 > > > > > > > > > > > > Could someone try this patch against Linus' tree? > > > > > > Urgh, and here's a version that isn't utterly, utterly broken... > > > > Thanks for Matt's patch, we will try it! > > > > Joey Lee > > Frederic confirmed your patch works to him for fix issue on HP > machine. > > Tested-by: Frederic Crozat Sorry forgot paste variable_name_size from log: efivars: bogus variable_name_size: 34 1024 efivars: bogus variable_name_size: 22 1024 The GetNextVariable() always return variable_name_size is 1024. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/