diff --git a/fix-dentry-hash.patch b/fix-dentry-hash.patch new file mode 100644 index 000000000..c5b2f4774 --- /dev/null +++ b/fix-dentry-hash.patch @@ -0,0 +1,113 @@ +From davej Thu Mar 22 16:38:38 2012 +Return-Path: linux-kernel-owner@vger.kernel.org +X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on + gelk.kernelslacker.org +X-Spam-Level: +X-Spam-Status: No, score=-1.2 required=5.0 tests=KB_DATE_CONTAINS_TAB, + RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=unavailable + version=3.3.2 +Received: from mail.corp.redhat.com [10.5.5.51] + by gelk.kernelslacker.org with IMAP (fetchmail-6.3.21) + for (single-drop); Thu, 22 Mar 2012 16:38:38 -0400 (EDT) +Received: from zmta02.collab.prod.int.phx2.redhat.com (LHLO + zmta02.collab.prod.int.phx2.redhat.com) (10.5.5.32) by + zmail11.collab.prod.int.phx2.redhat.com with LMTP; Thu, 22 Mar 2012 + 16:37:12 -0400 (EDT) +Received: from localhost (localhost.localdomain [127.0.0.1]) + by zmta02.collab.prod.int.phx2.redhat.com (Postfix) with ESMTP id BE4B31280F5; + Thu, 22 Mar 2012 16:37:12 -0400 (EDT) +X-Quarantine-ID: +Received: from zmta02.collab.prod.int.phx2.redhat.com ([127.0.0.1]) + by localhost (zmta02.collab.prod.int.phx2.redhat.com [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id rVyHUDnYJs0w; Thu, 22 Mar 2012 16:37:12 -0400 (EDT) +Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) + by zmta02.collab.prod.int.phx2.redhat.com (Postfix) with ESMTP id 34CCC1280EF; + Thu, 22 Mar 2012 16:37:12 -0400 (EDT) +Received: from mx1.redhat.com (ext-mx14.extmail.prod.ext.phx2.redhat.com [10.5.110.19]) + by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q2MKbBbO012811; + Thu, 22 Mar 2012 16:37:11 -0400 +Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) + by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q2MIJPCS018091; + Thu, 22 Mar 2012 16:37:10 -0400 +Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand + id S1759738Ab2CVUhD (ORCPT + 54 others); + Thu, 22 Mar 2012 16:37:03 -0400 +Received: from zeniv.linux.org.uk ([195.92.253.2]:35901 "EHLO + ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org + with ESMTP id S1758619Ab2CVUg7 (ORCPT + ); + Thu, 22 Mar 2012 16:36:59 -0400 +Received: from viro by ZenIV.linux.org.uk with local (Exim 4.76 #1 (Red Hat Linux)) + id 1SAokk-0008Fi-MR; Thu, 22 Mar 2012 20:36:58 +0000 +Date: Thu, 22 Mar 2012 20:36:58 +0000 +From: Al Viro +To: Linus Torvalds +Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, + Konrad Rzeszutek Wilk +Subject: Re: Regression introduced by + bfcfaa77bdf0f775263e906015982a608df01c76 (vfs: use 'unsigned long' accesses + for dcache name comparison and hashing) +Message-ID: <20120322203658.GC6589@ZenIV.linux.org.uk> +References: <20120322183845.GA17264@phenom.dumpdata.com> + <20120322200918.GZ6589@ZenIV.linux.org.uk> + <20120322202445.GB6589@ZenIV.linux.org.uk> +MIME-Version: 1.0 +Content-Type: text/plain; charset=us-ascii +Content-Disposition: inline +In-Reply-To: <20120322202445.GB6589@ZenIV.linux.org.uk> +User-Agent: Mutt/1.5.21 (2010-09-15) +Sender: linux-kernel-owner@vger.kernel.org +Precedence: bulk +List-ID: +X-Mailing-List: linux-kernel@vger.kernel.org +X-RedHat-Spam-Score: -5.01 (RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD) +X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 +X-Scanned-By: MIMEDefang 2.68 on 10.5.110.19 +Status: RO +Content-Length: 1440 +Lines: 43 + +On Thu, Mar 22, 2012 at 08:24:45PM +0000, Al Viro wrote: +> +> OK, full_name_hash()/hash_name() definitely have a mismatch and it's on the +> names of length 8*n: trivial experiment shows that we have +> name hash_name full_name_hash +> a 61 61 +> ab 6261 6261 +> abc 636261 636261 +> abcd 64636261 64636261 +> abcdabc 64c6c4c2 64c6c4c2 +> abcdabcd efcead5 c8c6c4c2 +> abcdabcd9 efceb0e efceb0e +> +> Linus, which way do you prefer to shift it? Should hash_name() change to +> match full_name_hash() or should it be the other way round? +> +> What happens is that you get multiplication by 9 and adding 0 in the former, +> after having added the last full word. In the latter we add the last full +> word, see that there's nothing left and bugger off. + +Guys, could you check if this fixes it? + +diff --git a/fs/namei.c b/fs/namei.c +index 13e6a1f..7451d6f8 100644 +--- a/fs/namei.c ++++ b/fs/namei.c +@@ -1439,10 +1439,10 @@ unsigned int full_name_hash(const unsigned char *name, unsigned int len) + + for (;;) { + a = *(unsigned long *)name; +- hash *= 9; + if (len < sizeof(unsigned long)) + break; + hash += a; ++ hash *= 9; + name += sizeof(unsigned long); + len -= sizeof(unsigned long); + if (!len) +-- +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/ + diff --git a/kernel.spec b/kernel.spec index f4fea4b94..5abf4079b 100644 --- a/kernel.spec +++ b/kernel.spec @@ -766,6 +766,8 @@ Patch21400: unhandled-irqs-switch-to-polling.patch Patch22000: weird-root-dentry-name-debug.patch +Patch23000: fix-dentry-hash.patch + %endif BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root @@ -1473,6 +1475,8 @@ ApplyPatch unhandled-irqs-switch-to-polling.patch ApplyPatch weird-root-dentry-name-debug.patch +ApplyPatch fix-dentry-hash.patch + #rhbz 803809 CVE-2012-1179 ApplyPatch mm-thp-fix-pmd_bad-triggering.patch @@ -2332,6 +2336,9 @@ fi # ||----w | # || || %changelog +* Thu Mar 22 2012 Dave Jones +- Fix dentry hash collisions that prevented boot with selinux enabled (rhbz 805371) + * Thu Mar 22 2012 Dave Jones 3.4.0-0.rc0.git1.1 - Linux v3.3-4074-g5375871