From nobody Sat Feb 7 17:55:30 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 995A315ECCC; Sat, 20 Dec 2025 06:41:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766212915; cv=none; b=uqij0RlxdmV+2ib1tKtRdXoiMVdnFMIvxJbJ+gzE2JcYdqICeRp7+zBQ86RFjs8GKbeYe2Mt/xOAGDfqoocRHoF2FZvJLg640sx0as4xH7pY3yc1uV4mOhCUqFrG5gwa3D++MOz8MlRFFYtH1XyyRbnK7OkwmzkbZWtPdZK/osc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766212915; c=relaxed/simple; bh=0cYM1OGkisWER17OI/JlqgHBJhvaSLpBwGWv79i5mOY=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=BZ4PodzudSygnEfcm96nHYrVWeNkhHLLmPrD7iyAitgYjFg/YEDyS/yXTjOKSRhCANhhwk1qRQCcr8It3f22j0XpOCpvU+XSY9PQaBIsyhqZx64Zh3IHgV49kmjs1KD+wrQQxoDTFf+WpclgYEMq7erF4Bw5/vzpFPJ47LDXsVU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R6Q8HXfT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R6Q8HXfT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 579CBC4CEF5; Sat, 20 Dec 2025 06:41:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766212915; bh=0cYM1OGkisWER17OI/JlqgHBJhvaSLpBwGWv79i5mOY=; h=Date:From:To:Cc:Subject:From; b=R6Q8HXfTaM1mxlpJVIInwBxbjdVI3LZKbiEc4Y9Ka11Ok7k0FSQjGLVXkZLaWWm+s EJlfpPDnsCIxsbC9wWD/yEQ0Y0X9XSLmF1DcJ9PW/auxENjIieuwt1xXSH6pigyefK h1PYhZcRXnUPfEK2PxEjlUgbNIX9di3ZTDq1uRF+aO2rBOF0DNPLJuy3Colf+piyjB NChFEH7uIp9NFUIESMXvrAzhIkh+wi2E6QPq9xzfkvUt/z1jaUHQFAEKSJku1puAv/ eq3stnViZdZrpWZ11mjaZZ1dWzZsYhKG7RRlke9BqHJhVW986sYBEUjlhn4UNmrSFI IGv4/SkPwBD0w== Date: Sat, 20 Dec 2025 15:41:49 +0900 From: "Gustavo A. R. Silva" To: Randy Dunlap , Alexander Usyskin , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rodrigo Vivi , Raag Jadav , Tomas Winkler Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH] mtd: intel-dg: fix array-index-out-of-bounds in intel_dg_mtd_probe() Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Fix the UBSAN: array-index-out-of-bounds issue below by updating counter nvm->nregions before the first access to flexible-array member nvm->regions[]. from kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=3D220823 Dec 15 22:01:52 orpheus kernel: UBSAN: array-index-out-of-bounds in /var/tm= p/portage/sys-kernel/gentoo-kernel-6.18.1/work/linux-6.18/drivers/mtd/devic= es/mtd_intel_dg.c:750:15 Notice that this flexible array is annotated with the counted_by() attribute, hence the counter must always be updated before the first access to the array. Cc: stable@vger.kernel.org Fixes: ceb5ab3cb646 ("mtd: add driver for intel graphics non-volatile memor= y device") Reported-by: Randy Dunlap Closes: https://lore.kernel.org/linux-hardening/90e419ad-4036-4669-a4cc-8ce= 5d29e464b@infradead.org/ Signed-off-by: Gustavo A. R. Silva Acked-by: Randy Dunlap --- drivers/mtd/devices/mtd_intel_dg.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mtd/devices/mtd_intel_dg.c b/drivers/mtd/devices/mtd_i= ntel_dg.c index 2bab30dcd35f..d3e89fe324b8 100644 --- a/drivers/mtd/devices/mtd_intel_dg.c +++ b/drivers/mtd/devices/mtd_intel_dg.c @@ -768,6 +768,9 @@ static int intel_dg_mtd_probe(struct auxiliary_device *= aux_dev, if (!nvm) return -ENOMEM; =20 + /* Update nvm->nregions before first access to nvm->regions[] below. */ + nvm->nregions =3D nregions; + kref_init(&nvm->refcnt); mutex_init(&nvm->lock); =20 --=20 2.43.0