linux-kernel - Re: [PATCH mm-unstable 1/2] mseal sysmap: generic vdso vvar mapping

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: <3f2f341b-6e18-4850-8b9c-bac16906edb5@lucifer.local>
Date: Tue, 11 Mar 2025 14:36:07 +0000
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Heiko Carstens <hca@...ux.ibm.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>, Jeff Xu <jeffxu@...omium.org>,
        "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Kees Cook <kees@...nel.org>,
        Thomas Weißschuh <thomas.weissschuh@...utronix.de>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Sven Schnelle <svens@...ux.ibm.com>, Vasily Gorbik <gor@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linux-hardening@...r.kernel.org
Subject: Re: [PATCH mm-unstable 1/2] mseal sysmap: generic vdso vvar mapping

On Tue, Mar 11, 2025 at 01:33:25PM +0100, Heiko Carstens wrote:
> With the introduction of the generic vdso data storage the VM_SEALED_SYSMAP
> vm flag must be moved from the architecture specific
> _install_special_mapping() call [1] [2] which maps the vvar mapping to
> generic code.
>
> [1] https://lkml.kernel.org/r/20250305021711.3867874-4-jeffxu@google.com
> [2] https://lkml.kernel.org/r/20250305021711.3867874-5-jeffxu@google.com
>
> Signed-off-by: Heiko Carstens <hca@...ux.ibm.com>

Since CONFIG_MSEAL_SYSTEM_MAPPINGS this relies upon
ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS, this is safe to do in generic code
(otherwise VM_SEALED_SYSMAP is VM_NONE).

So all good and:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>

> ---
>  lib/vdso/datastore.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/vdso/datastore.c b/lib/vdso/datastore.c
> index e227fbbcb796..b7c7386c98a9 100644
> --- a/lib/vdso/datastore.c
> +++ b/lib/vdso/datastore.c
> @@ -99,7 +99,8 @@ const struct vm_special_mapping vdso_vvar_mapping = {
>  struct vm_area_struct *vdso_install_vvar_mapping(struct mm_struct *mm, unsigned long addr)
>  {
>  	return _install_special_mapping(mm, addr, VDSO_NR_PAGES * PAGE_SIZE,
> -					VM_READ | VM_MAYREAD | VM_IO | VM_DONTDUMP | VM_PFNMAP,
> +					VM_READ | VM_MAYREAD | VM_IO | VM_DONTDUMP |
> +					VM_PFNMAP | VM_SEALED_SYSMAP,
>  					&vdso_vvar_mapping);
>  }
>
> --
> 2.45.2
>