From: Will Deacon <will@kernel.org>
To: catalin.marinas@arm.com, Dev Jain <dev.jain@arm.com>
Cc: kernel-team@android.com, Will Deacon <will@kernel.org>,
gshan@redhat.com, rppt@kernel.org, steven.price@arm.com,
suzuki.poulose@arm.com, tianyaxiong@kylinos.cn, ardb@kernel.org,
david@redhat.com, ryan.roberts@arm.com, urezki@gmail.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] arm64: pageattr: Explicitly bail out when changing permissions for vmalloc_huge mappings
Date: Tue, 29 Apr 2025 21:27:45 +0100 [thread overview]
Message-ID: <174594039520.474971.2876521667626295214.b4-ty@kernel.org> (raw)
In-Reply-To: <20250403052844.61818-1-dev.jain@arm.com>
On Thu, 03 Apr 2025 10:58:44 +0530, Dev Jain wrote:
> arm64 uses apply_to_page_range to change permissions for kernel vmalloc mappings,
> which does not support changing permissions for block mappings. This function
> will change permissions until it encounters a block mapping, and will bail
> out with a warning. Since there are no reports of this triggering, it
> implies that there are currently no cases of code doing a vmalloc_huge()
> followed by partial permission change. But this is a footgun waiting to
> go off, so let's detect it early and avoid the possibility of permissions
> in an intermediate state. So, explicitly disallow changing permissions
> for VM_ALLOW_HUGE_VMAP mappings.
>
> [...]
Applied to arm64 (for-next/mm), thanks!
[1/1] arm64: pageattr: Explicitly bail out when changing permissions for vmalloc_huge mappings
https://git.kernel.org/arm64/c/fcf8dda8cc48
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
prev parent reply other threads:[~2025-04-29 20:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-03 5:28 Dev Jain
2025-04-03 9:31 ` Anshuman Khandual
2025-04-04 9:43 ` Gavin Shan
2025-04-04 12:57 ` David Hildenbrand
2025-04-14 13:48 ` Ryan Roberts
2025-04-27 14:35 ` Dev Jain
2025-04-29 20:27 ` Will Deacon [this message]
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