linux-kernel - Re: [PATCH] powerpc: Fix mprotect on book3s32

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] [day] [month] [year] [list]

Message-ID: <baf4fd6c-1796-47cb-a9bb-72521a217453@vasilevsky.ca>
Date: Sat, 8 Nov 2025 17:24:44 -0500
From: Dave Vasilevsky <dave@...ilevsky.ca>
To: "Ritesh Harjani (IBM)" <ritesh.list@...il.com>,
 Madhavan Srinivasan <maddy@...ux.ibm.com>,
 Michael Ellerman <mpe@...erman.id.au>, Nicholas Piggin <npiggin@...il.com>,
 Christophe Leroy <christophe.leroy@...roup.eu>,
 Nadav Amit <nadav.amit@...il.com>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 Andrew Morton <akpm@...ux-foundation.org>
Cc: linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
 stable@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH] powerpc: Fix mprotect on book3s32

On 2025-11-08 14:16, Ritesh Harjani wrote: 
> Shouldn't we flush all if we get tlb_flush request for full mm? e.g.
> Something like this maybe? 
> 
> +void hash__tlb_flush(struct mmu_gather *tlb)
> +{
> +       if (tlb->fullmm || tlb->need_flush_all)
> +               hash__flush_tlb_mm(tlb->mm);
> +       else
> +               hash__flush_range(tlb->mm, tlb->start, tlb->end);
> +}

That seems reasonable, I should be able to test it next by next
weekend and re-submit.

> Thanks again for pointing this out. How did you find this though?
> What hardware do you use?

I'm on an iBook G3 from 2001, running Arch Power:
https://archlinuxpower.org/. I found the bug because SheepShaver has a
configure test for mprotect, which was failing--I was quite surprised!

The bug reproduces easily on qemu (with the `mac99` machine), if you'd
like to try yourself.

-Dave