linux-kernel - Re: [PATCH 1/5] module: Fix module_sig_check() for modules with ignored modversions/vermagic

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Message-ID: <CABCJKucGtbZw_DCpnbUr7cQeU+_DF97YTeDVgPX7tTyPwNabog@mail.gmail.com>
Date: Fri, 22 Aug 2025 12:36:47 -0700
From: Sami Tolvanen <samitolvanen@...gle.com>
To: Jinchao Wang <wangjinchao600@...il.com>
Cc: Luis Chamberlain <mcgrof@...nel.org>, Petr Pavlu <petr.pavlu@...e.com>, 
	Daniel Gomez <da.gomez@...nel.org>, linux-modules@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/5] module: Fix module_sig_check() for modules with
 ignored modversions/vermagic

On Fri, Aug 22, 2025 at 5:55 AM Jinchao Wang <wangjinchao600@...il.com> wrote:
>
> The current signature check logic incorrectly fails modules that have
> valid signatures when the caller specifies MODULE_INIT_IGNORE_MODVERSIONS
> or MODULE_INIT_IGNORE_VERMAGIC flags. This happens because the code
> treats these flags as indicating a "mangled module" and skips signature
> verification entirely.
>
> The key insight is that the intent of the caller (to ignore modversions
> or vermagic) should not affect signature verification. A module with
> a valid signature should be verified regardless of whether the caller
> wants to ignore versioning information.

Why would you need to ignore versions when loading signed modules?
Here's the original series that added this check and I feel it's very
much relevant still:

https://lore.kernel.org/lkml/20160423184421.GL3348@decadent.org.uk/

Sami