linux-kernel - Re: [PATCH] x86/mm: Fix log overwrite in CPA 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-prev] [day] [month] [year] [list]

Message-ID: <20250620182659.603-1-khaliidcaliy@gmail.com>
Date: Fri, 20 Jun 2025 18:20:58 +0000
From: Khalid Ali <khaliidcaliy@...il.com>
To: peterz@...radead.org
Cc: dave.hansen@...ux.intel.com,
	luto@...nel.org,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	x86@...nel.org,
	hpa@...or.c,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86/mm: Fix log overwrite in CPA check_conflict()

> > From: Khalid Ali <khaliidcaliy@...il.com>
> > 
> > On certain configurations (e.g. custom builds), check_conflict()
> > may produce a large number of warnings, flooding the kernel log
> > and overwriting earlier messages.
> > 
> > Observed warning:
> > 
> >   CPA  protect  Rodata RO: 0xffff888022a75000 - 0xffff888022a75fff
> >         PFN 22a75 req 8000000000000023 prevent 0000000000000002

> That's not good. Your system is sick, limiting the warns isn't making
>that better.

There is nothing wrong. It is just misconfiguration, however i don't see why 
it is neccessary this warning to spam the dmesg log. Maybe it is better idea 
to limit printing warning instead of warning for every page in a section (i.e Rodata in my case)
would make sense. So by limiting logs in anyways is good. 

There is also overhead by logging if that happens. 

Thanks
Khalid Ali