From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35554 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755963AbdCTRd4 (ORCPT ); Mon, 20 Mar 2017 13:33:56 -0400 Subject: Patch "x86/intel_rdt: Put group node in rdtgroup_kn_unlock" has been added to the 4.10-stable tree To: jolsa@kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, fenghua.yu@intel.com, gregkh@linuxfoundation.org, peterz@infradead.org, shli@fb.com, tglx@linutronix.de Cc: , From: Date: Mon, 20 Mar 2017 18:33:26 +0100 Message-ID: <149003120625251@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/intel_rdt: Put group node in rdtgroup_kn_unlock to the 4.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-intel_rdt-put-group-node-in-rdtgroup_kn_unlock.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 49ec8f5b6ae3ab60385492cad900ffc8a523c895 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 14 Mar 2017 15:20:53 +0100 Subject: x86/intel_rdt: Put group node in rdtgroup_kn_unlock From: Jiri Olsa commit 49ec8f5b6ae3ab60385492cad900ffc8a523c895 upstream. The rdtgroup_kn_unlock waits for the last user to release and put its node. But it's calling kernfs_put on the node which calls the rdtgroup_kn_unlock, which might not be the group's directory node, but another group's file node. This race could be easily reproduced by running 2 instances of following script: mount -t resctrl resctrl /sys/fs/resctrl/ pushd /sys/fs/resctrl/ mkdir krava echo "krava" > krava/schemata rmdir krava popd umount /sys/fs/resctrl It triggers the slub debug error message with following command line config: slub_debug=,kernfs_node_cache. Call kernfs_put on the group's node to fix it. Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system") Signed-off-by: Jiri Olsa Cc: Fenghua Yu Cc: Peter Zijlstra Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Shaohua Li Link: http://lkml.kernel.org/r/1489501253-20248-1-git-send-email-jolsa@kernel.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -727,7 +727,7 @@ void rdtgroup_kn_unlock(struct kernfs_no if (atomic_dec_and_test(&rdtgrp->waitcount) && (rdtgrp->flags & RDT_DELETED)) { kernfs_unbreak_active_protection(kn); - kernfs_put(kn); + kernfs_put(rdtgrp->kn); kfree(rdtgrp); } else { kernfs_unbreak_active_protection(kn); Patches currently in stable-queue which might be from jolsa@kernel.org are queue-4.10/x86-intel_rdt-put-group-node-in-rdtgroup_kn_unlock.patch