linux-kernel - [PATCH v3] mm: Fix mremap not considering huge pmd devmap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 4 Jun 2020 23:53:45 +0530
From:   Ajay Kaher <akaher@...are.com>
To:     <fan_yang@...u.edu.cn>
CC:     <dan.j.williams@...el.com>, <kirill.shutemov@...ux.intel.com>,
        <linux-kernel@...r.kernel.org>, <torvalds@...ux-foundation.org>,
        <gregkh@...uxfoundation.org>, <srivatsab@...are.com>,
        <srivatsa@...il.mit.edu>, <akaher@...are.com>
Subject: [PATCH v3] mm: Fix mremap not considering huge pmd devmap

Hi Fan,

Able to reproduce this issue on v4.19.y using your test program.

And as per commit message it fixes commit 5c7fb56e5e3f 
("mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pm”) at kernel version v4.5.
So, v4.9.y should be vulnerable, however not able to reproduce on v4.9.y.
Does any specific scenerio need to test for v4.9.y?

For v4.9, modified test program as MAP_SHARED_VALIDATE is not available:
- return mmap(NULL, REGION_PM_SIZE, PROT, MAP_SHARED_VALIDATE|MAP_SYNC,
+ return mmap(NULL, REGION_PM_SIZE, PROT, MAP_SHARED|MAP_SYNC,

Let me know if I need to test some other way for v4.9.y.

-Ajay