From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 113F7224D6 for ; Thu, 26 Sep 2024 09:34:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727343243; cv=none; b=Zt48oigKmjjaX2mZGtfRFzKc5jEtiJsjBGeL+3/zv+DujCm1XXS7zDjlC2PZPZd9D0LZ8c1QXgBaMYQy3Jtq/PXWQfrJnmNLGB6ZfuUf02jzcXpG5dRtAWVv8FWfI8Kc+H4BaZYjJd+QzPfXc3wA2+whUmTMEsPQRQlx4iU7enw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727343243; c=relaxed/simple; bh=Df5Y9+CiHpGGKQOzwFg0ep4DadWij8jUa5ykfjb2WLg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hhBLUcUL8HRLQVswaR6T00YPsKTW8qbMRPjqINQISHMQpPz7RTo2S5UY5zl6PsWqme9ZOVGGCRx+5qVG1SSo5QxlLlxh+IjwhB6iEAphbeC1rQdjrfQSPYRsoKkPjpXajkvN8J60mvLjJn1q5aqdDggNSJliCzazozJRLDJlz88= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=LUI9tduO; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="LUI9tduO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1727343240; bh=Df5Y9+CiHpGGKQOzwFg0ep4DadWij8jUa5ykfjb2WLg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LUI9tduOcNBvZPpnTbgYRam64lWcZhKujisk4t/35GFgvZ3/st0pJn2jrXSu2Lam/ Gx47u64L0EkRtup8c5zi8swKwdFlx+VVe7hNov7e3ADoinAftAd76eU7zuq+HxTjnC 3nAtsNaz0uSLtWynTVo4uMw6aIk7jVob4wcZG0JzCgJU7pZCzpLNcGrFJVYdKsz7HK jDX1G+UG1G76vTDUzqWghRCbx7RcZZkZgveShv9jaXsmoYbcs/0wV9fGORZ5AUW2TN wlvkAcEaJSeG8jOFcRyzWjw598PAtHi7g0GXzvExvy4ERbfmz8rapp2Rp7/L+rCD0B +e5zymaIdn3ug== Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id A271117E10AE; Thu, 26 Sep 2024 11:33:59 +0200 (CEST) Message-ID: Date: Thu, 26 Sep 2024 11:33:59 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read To: Liankun Yang , chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@gmail.com, simona@ffwll.ch, matthias.bgg@gmail.com, rex-bc.chen@mediatek.com, msp@baylibre.com, granquet@baylibre.com, dmitry.osipenko@collabora.com, jitao.shi@mediatek.com, mac.shen@mediatek.com, peng.liu@mediatek.com Cc: Project_Global_Chrome_Upstream_Group@mediatek.com, dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20240925084116.28848-1-liankun.yang@mediatek.com> From: AngeloGioacchino Del Regno Content-Language: en-US In-Reply-To: <20240925084116.28848-1-liankun.yang@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Il 25/09/24 10:40, Liankun Yang ha scritto: > If the len is 0, kernel crash will occur when performing operations. > Add the len check conditions to prevent kernel crash. > Please fix the commit title: drm/mediatek: mtk_dp: Fix potential KP on 0 bytes nvmem cell read > Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") > Please remove this blank line between the Fixes tag and your S-o-b. > Signed-off-by: Liankun Yang > --- > drivers/gpu/drm/mediatek/mtk_dp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c > index d8796a904eca..0cc75ba96b98 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dp.c > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c > @@ -1082,7 +1082,7 @@ static void mtk_dp_get_calibration_data(struct mtk_dp *mtk_dp) > buf = (u32 *)nvmem_cell_read(cell, &len); > nvmem_cell_put(cell); > > - if (IS_ERR(buf) || ((len / sizeof(u32)) != 4)) { > + if (IS_ERR(buf) || (len == 0) || ((len / sizeof(u32)) != 4)) { if (IS_ERR(buf) || !len || ((len / sizeof(u32)) != 4)) { Cheers, Angelo