linux-kernel - Re: [PATCH] of_reserved_mem: Save region name string into struct reserved

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]

Message-ID: <ee79c94a-c09a-4390-bb8a-65f01ddcf6e0@kernel.org>
Date: Sun, 25 Aug 2024 10:03:30 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Jiaxun Yang <jiaxun.yang@...goat.com>
Cc: Rob Herring <robh@...nel.org>, Saravana Kannan <saravanak@...gle.com>,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 loongarch@...ts.linux.dev, chenhuacai@...nel.org,
 Kevin Wheatfox <enkerewpo@...mail.com>
Subject: Re: [PATCH] of_reserved_mem: Save region name string into struct
 reserved_mem

On 25/08/2024 09:18, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2024 at 02:51:02PM +0100, Jiaxun Yang wrote:
>> Previously only a pointer to fdt string pool is saved to struct
>> reserved_mem as region name.
>>
>> As on some architectures booting FDT will be wiped at later initialisation
>> stages, this is breaking reserved_mem users.
>>
>> Copy and save the whole string into struct reserved_mem to avoid
>> FDT lifecycle problem.
>>
>> Reported-by: Kevin Wheatfox <enkerewpo@...mail.com>
>> Closes: https://lore.kernel.org/loongarch/ME4P282MB1397447C3C094554C7AF2E37B58E2@ME4P282MB1397.AUSP282.PROD.OUTLOOK.COM/
> 
> I doubt this uses mainline tree...
> 
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@...goat.com>
> 
> This is a bigger problem and should be solved unified way in multiple
> places. You cannot just wipe out FDT from the memory, because it is used
> in all other places.
> 
> Your report earlier probably used some custom patches allowing this
> wipe out, but that's the mistake. Fix your wiping out mechanism...

The commit msg is quite vague on real problem, so one has to go to
original report to find that you use built-in dtb, so only the
unflatten_and_copy_device_tree() path, while I have impression you just
want to drop the copied (in-kernel) FDT.

Fix the commit msg to describe the real problem being fixed here.
Provide also proper fixes tag.

Best regards,
Krzysztof