linux-kernel - mprotect outbound check.

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-next>] [day] [month] [year] [list]

Message-ID: <CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@mail.gmail.com>
Date:   Mon, 15 May 2023 11:00:27 -0700
From:   Jeff Xu <jeffxu@...omium.org>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, linux-hardening@...r.kernel.org,
        Jorge Lucangeli Obes <jorgelo@...omium.org>
Subject: mprotect outbound check.

Noticed there is a slight change for mprotect between 6.1 and 6.4 RC1

For example:
Consider the case below:
1 mmap(0x5000000, PAGE_SIZE,  ...)
2 mprotect(0x5000000, PAGE_SIZE*4, ...)

in 6.1 and before, 2 will fail, and in 6.4 RC1, it will pass.

I know that munmap will accept out-of-bound cases like this (because
memory is freed anyway).

Is this change intentional ?

Thanks!
Best regards,
-Jeff