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From: Pratyush Yadav <pratyush@kernel.org>
To: Tarun Sahu <tarunsahu@google.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>,
	 Mike Rapoport <rppt@kernel.org>,
	 Pratyush Yadav <pratyush@kernel.org>,
	 Andrew Morton <akpm@linux-foundation.org>,
	 linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
	 linux-mm@kvack.org
Subject: Re: [PATCH] mm/memfd_luo: validate serialized_data before conversion
Date: Thu, 11 Jun 2026 14:32:51 +0200	[thread overview]
Message-ID: <2vxzv7bpqmto.fsf@kernel.org> (raw)
In-Reply-To: <c2478f79207b10a13282d917c961261d17b86a15.1781173768.git.tarunsahu@google.com> (Tarun Sahu's message of "Thu, 11 Jun 2026 10:30:03 +0000")

On Thu, Jun 11 2026, Tarun Sahu wrote:

> In memfd_luo_finish() and memfd_luo_retrieve(), phys_to_virt() was called
> on args->serialized_data before checking if the physical address is valid.
> Since physical address 0 does not map to virtual NULL (due to direct

Nit: this is only true on ARM64. On x86 physical address of 0 maps to
NULL.

Other than this,

Reviewed-by: Pratyush Yadav (Google) <pratyush@kernel.org>

> mapping offsets), the subsequent check 'if (!ser)' was ineffective at
> catching a missing serialized_data, leading to unsafe dereferences later.
>
> Validate that args->serialized_data is non-zero before calling
> phys_to_virt().
>
> Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd")
> Signed-off-by: Tarun Sahu <tarunsahu@google.com>
[...]

-- 
Regards,
Pratyush Yadav

  reply	other threads:[~2026-06-11 12:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-11 10:30 [PATCH] mm/memfd_luo: validate serialized_data before conversion Tarun Sahu
2026-06-11 12:32 ` Pratyush Yadav [this message]
2026-06-11 12:40 ` Mike Rapoport
2026-06-11 13:37   ` Pratyush Yadav
2026-06-11 14:28     ` Mike Rapoport
2026-06-11 18:11       ` Pasha Tatashin
2026-06-11 18:11 ` Pasha Tatashin

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