Linux PCI subsystem development
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From: "Krzysztof Wilczyński" <kwilczynski@kernel.org>
To: sashiko-reviews@lists.linux.dev
Cc: linux-pci@vger.kernel.org
Subject: Re: [PATCH 1/4] PCI/sysfs: Stop reporting _DSM failures as -EPERM
Date: Fri, 14 Aug 2026 18:36:03 +0900	[thread overview]
Message-ID: <20260814093533.GB3463973@rocinante> (raw)
In-Reply-To: <20260814071901.78AA11F000E9@smtp.kernel.org>

Hello,

> [Severity: High]
> This isn't a bug introduced by this patch, but does this code cause a buffer
> over-read?
> 
> It appears utf16s_to_utf8s() expects the maximum number of 16-bit characters
> as its second argument, but it is being passed obj->buffer.length in bytes.
> 
> If a PCI device with a firmware-provided ACPI _DSM returns a
> non-NUL-terminated buffer of UTF-16 characters, could this read past the end
> of the allocation when a user reads the world-readable sysfs label attribute?
> 
> Should the length be divided by sizeof(wchar_t) to prevent reading out of
> bounds?

The last patch of this series aims to address this issue.

Thank you!

	Krzysztof

  reply	other threads:[~2026-08-14  9:36 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-14  7:05 [PATCH 0/4] PCI/sysfs: Fix the ACPI device name attributes Krzysztof Wilczyński
2026-08-14  7:05 ` [PATCH 1/4] PCI/sysfs: Stop reporting _DSM failures as -EPERM Krzysztof Wilczyński
2026-08-14  7:19   ` sashiko-bot
2026-08-14  9:36     ` Krzysztof Wilczyński [this message]
2026-08-14  7:05 ` [PATCH 2/4] PCI/sysfs: Decouple acpi_index from the optional device name element Krzysztof Wilczyński
2026-08-14  7:11   ` sashiko-bot
2026-08-14  7:05 ` [PATCH 3/4] PCI/sysfs: Handle a malformed _DSM result in acpi_attr_is_visible() Krzysztof Wilczyński
2026-08-14  7:19   ` sashiko-bot
2026-08-14  9:35     ` Krzysztof Wilczyński
2026-08-14  7:05 ` [PATCH 4/4] PCI/sysfs: Pass the device name length in UTF-16 code units Krzysztof Wilczyński
2026-08-14  7:14   ` sashiko-bot
2026-08-14 10:22   ` Krzysztof Wilczyński
2026-08-14  9:45 ` [PATCH 0/4] PCI/sysfs: Fix the ACPI device name attributes Krzysztof Wilczyński

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