Patch "mm/memory.c: fix mem_cgroup_oom_disable() call missing" has been added to the 4.12-stable tree

Patch "mm/memory.c: fix mem_cgroup_oom_disable() call missing" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm/memory.c: fix mem_cgroup_oom_disable() call missing

to the 4.12-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:
     mm-memory.c-fix-mem_cgroup_oom_disable-call-missing.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From de0c799bba2610a8e1e9a50d76a28614520a4cd4 Mon Sep 17 00:00:00 2001
From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Date: Fri, 8 Sep 2017 16:13:12 -0700
Subject: mm/memory.c: fix mem_cgroup_oom_disable() call missing

From: Laurent Dufour <ldufour@linux.vnet.ibm.com>

commit de0c799bba2610a8e1e9a50d76a28614520a4cd4 upstream.

Seen while reading the code, in handle_mm_fault(), in the case
arch_vma_access_permitted() is failing the call to
mem_cgroup_oom_disable() is not made.

To fix that, move the call to mem_cgroup_oom_enable() after calling
arch_vma_access_permitted() as it should not have entered the memcg OOM.

Link: http://lkml.kernel.org/r/1504625439-31313-1-git-send-email-ldufour@linux.vnet.ibm.com
Fixes: bae473a423f6 ("mm: introduce fault_env")
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/memory.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3843,6 +3843,11 @@ int handle_mm_fault(struct vm_area_struc
 	/* do counter updates before entering really critical section. */
 	check_sync_rss_stat(current);
 
+	if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
+					    flags & FAULT_FLAG_INSTRUCTION,
+					    flags & FAULT_FLAG_REMOTE))
+		return VM_FAULT_SIGSEGV;
+
 	/*
 	 * Enable the memcg OOM handling for faults triggered in user
 	 * space.  Kernel faults are handled more gracefully.
@@ -3850,11 +3855,6 @@ int handle_mm_fault(struct vm_area_struc
 	if (flags & FAULT_FLAG_USER)
 		mem_cgroup_oom_enable();
 
-	if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
-					    flags & FAULT_FLAG_INSTRUCTION,
-					    flags & FAULT_FLAG_REMOTE))
-		return VM_FAULT_SIGSEGV;
-
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
 	else


Patches currently in stable-queue which might be from ldufour@linux.vnet.ibm.com are

queue-4.12/mm-memory.c-fix-mem_cgroup_oom_disable-call-missing.patch