From: "Mickaël Salaün" <mic@digikod.net>
To: Kees Cook <kees@kernel.org>, Guo Ren <guoren@kernel.org>
Cc: linux-hardening@vger.kernel.org,
"kernel test robot" <lkp@intel.com>,
oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
"James Morris" <jamorris@linux.microsoft.com>,
"Jann Horn" <jannh@google.com>,
linux-csky@vger.kernel.org, "Günther Noack" <gnoack@google.com>
Subject: Re: security/landlock/ruleset.c:96:9: warning: 'memcpy' accessing 4294967295 bytes at offsets 20 and 0 overlaps 6442450943 bytes at offset -2147483648
Date: Fri, 21 Feb 2025 17:00:34 +0100 [thread overview]
Message-ID: <20250221.ga2OSh6ieZei@digikod.net> (raw)
In-Reply-To: <202501061623.7A617B09@keescook>
Cc csky developers.
See https://lore.kernel.org/r/202501040747.S3LYfvYq-lkp@intel.com
On Mon, Jan 06, 2025 at 04:27:26PM -0800, Kees Cook wrote:
> On Mon, Jan 06, 2025 at 06:04:56PM +0100, Mickaël Salaün wrote:
> > On Sat, Jan 04, 2025 at 07:26:27AM +0800, kernel test robot wrote:
> > > security/landlock/ruleset.c: In function 'create_rule':
> > > >> security/landlock/ruleset.c:96:9: warning: 'memcpy' accessing 4294967295 bytes at offsets 20 and 0 overlaps 6442450943 bytes at offset -2147483648 [-Wrestrict]
> > > 96 | memcpy(new_rule->layers, layers,
> > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > 97 | flex_array_size(new_rule, layers, num_layers));
> > > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This warning seems to only show with the csky architecture.
> >
> > I guess the GCC warning is a false positive?
> > See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116494
>
> Does the warning go away if flex_array_size() is open-coded or if the
> create_rule prototype uses "*" instead of "[]" syntax for the "layers"
> argument?
But that would not be correct right?
>
> The warning is about the "read" part ("accessing"). Using tip-of-tree
> gcc with -fdiagnostics-details might show more details on the calling
> path.
>
> -Kees
>
> --
> Kees Cook
>
parent reply other threads:[~2025-02-21 16:00 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <202501061623.7A617B09@keescook>]
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