linux-kernel - Re: [PATCH 1/3] x86: fix access_ok() and valid_user_address() using wrong USER_PTR

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: <20251106111429.GCaQyDFWjbN8PjqxUW@fat_crate.local>
Date: Thu, 6 Nov 2025 12:14:29 +0100
From: Borislav Petkov <bp@...en8.de>
To: Mateusz Guzik <mjguzik@...il.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
	the arch/x86 maintainers <x86@...nel.org>, brauner@...nel.org,
	viro@...iv.linux.org.uk, jack@...e.cz, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, tglx@...utronix.de, pfalcato@...e.de
Subject: Re: [PATCH 1/3] x86: fix access_ok() and valid_user_address() using
 wrong USER_PTR_MAX in modules

On Wed, Nov 05, 2025 at 09:50:51PM +0100, Mateusz Guzik wrote:
> For unrelated reasons I disassembled kmem_cache_free and the following
> goodies popped up:
> sub    0x18e033f(%rip),%rax        # ffffffff82f944d0 <page_offset_base>
> [..]
> add    0x18e031d(%rip),%rax        # ffffffff82f944c0 <vmemmap_base>
> [..]
> mov    0x2189e19(%rip),%rax        # ffffffff8383e010 <__pi_phys_base>
> 
> These are definitely worthwhile to get rid of.

Says which semi-respectable benchmark?

If none, why bother?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette