From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:40278 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759472AbcILO4j (ORCPT ); Mon, 12 Sep 2016 10:56:39 -0400 Subject: Patch "uprobes: Fix the memcg accounting" has been added to the 4.4-stable tree To: oleg@redhat.com, acme@kernel.org, acme@redhat.com, alexander.shishkin@linux.intel.com, alexei.starovoitov@gmail.com, bblanco@plumgrid.com, gregkh@linuxfoundation.org, hannes@cmpxchg.org, jolsa@redhat.com, mhocko@kernel.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, torvalds@linux-foundation.org, vdavydov@virtuozzo.com Cc: , From: Date: Mon, 12 Sep 2016 16:56:45 +0200 Message-ID: <147369220527100@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 uprobes: Fix the memcg accounting to the 4.4-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: uprobes-fix-the-memcg-accounting.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 17 Aug 2016 17:36:29 +0200 Subject: uprobes: Fix the memcg accounting From: Oleg Nesterov commit 6c4687cc17a788a6dd8de3e27dbeabb7cbd3e066 upstream. __replace_page() wronlgy calls mem_cgroup_cancel_charge() in "success" path, it should only do this if page_check_address() fails. This means that every enable/disable leads to unbalanced mem_cgroup_uncharge() from put_page(old_page), it is trivial to underflow the page_counter->count and trigger OOM. Reported-and-tested-by: Brenden Blanco Signed-off-by: Oleg Nesterov Reviewed-by: Johannes Weiner Acked-by: Michal Hocko Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vladimir Davydov Fixes: 00501b531c47 ("mm: memcontrol: rewrite charge API") Link: http://lkml.kernel.org/r/20160817153629.GB29724@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/events/uprobes.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -171,8 +171,10 @@ static int __replace_page(struct vm_area mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); err = -EAGAIN; ptep = page_check_address(page, mm, addr, &ptl, 0); - if (!ptep) + if (!ptep) { + mem_cgroup_cancel_charge(kpage, memcg); goto unlock; + } get_page(kpage); page_add_new_anon_rmap(kpage, vma, addr); @@ -199,7 +201,6 @@ static int __replace_page(struct vm_area err = 0; unlock: - mem_cgroup_cancel_charge(kpage, memcg); mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); unlock_page(page); return err; Patches currently in stable-queue which might be from oleg@redhat.com are queue-4.4/uprobes-fix-the-memcg-accounting.patch queue-4.4/cgroup-reduce-read-locked-section-of-cgroup_threadgroup_rwsem-during-fork.patch