From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout.web.de (mout.web.de [212.227.17.12]) (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 7DC541411EE; Thu, 27 Jun 2024 11:34:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719488047; cv=none; b=U6zLd0+px8T5+x7kASM3GucnoSrMO5eXmr+G96kmxm+E+4MgEA1EkVHWXuOGUAOiORMVFTx7IGtokkXtskOEkRD6BvprfgRdwfGDVA8Q61k5SrDozM+n3lJjoN7m5O37jvxwlasd9hlBBo5QgNq1bue/If4lWMbdAXoKDeXz3oM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719488047; c=relaxed/simple; bh=uhXbGazcXeqkxXjBouKM0MQuQ3CTfNGpf2RScCZD55M=; h=Message-ID:Date:MIME-Version:To:Cc:References:Subject:From: In-Reply-To:Content-Type; b=apuzxgPN68Fef9V9vx1JtOSm4jWrj2KE8VfS6cJ4F82GJz7Z9Ug/xebsEcOdBgPvUcGkL9DwVbw/Rhb3FSGWxR6LU+k0mWkq7oRl/pnGUz/hXt2DUGbDejaZLNY7q5zhJ8orCPHCT6l0/WJqLJB+Y/19PVQg+KIPcZCCILxSlkM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=web.de; spf=pass smtp.mailfrom=web.de; dkim=pass (2048-bit key) header.d=web.de header.i=markus.elfring@web.de header.b=bWfhjKvQ; arc=none smtp.client-ip=212.227.17.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=web.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=web.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=web.de header.i=markus.elfring@web.de header.b="bWfhjKvQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=web.de; s=s29768273; t=1719488022; x=1720092822; i=markus.elfring@web.de; bh=A7rM3y/OMnB34PKR/RnqFiGJ+fS+Qyq19jgyL7mRwdI=; h=X-UI-Sender-Class:Message-ID:Date:MIME-Version:To:Cc:References: Subject:From:In-Reply-To:Content-Type:Content-Transfer-Encoding: cc:content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=bWfhjKvQNMn2j1KF83zywHnz+eoZxC6KaKuZxFmkweB+9RqypJ1Ah6Ia+fGBWyUc wv2ZVxfjRKCUldkP+B4V7a8eytwO9I49N5dDLv8Z0DbspzNOW7v6nR13IJMbB1RnS kiZm9647+hc4Nd4WkG7ak+v1XNEyo8FrHIudpjqbgZBPkt6q4UbrcJ3c4tJzTjGu2 q9URQkqRnqAMqhx8OIKYUJult7ZEjOz0jyTMFdRttKZEmzyXs7Pde6/UtgIHcktLp PdtQyzTL0WNthjIl6kPn+Jphf5Kgo71LXqm65TO2Rf6XKf3X+NcpFME7YyUPYxACi FTgaA0+vys9tcV/XGg== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Received: from [192.168.178.21] ([94.31.91.95]) by smtp.web.de (mrweb106 [213.165.67.124]) with ESMTPSA (Nemesis) id 1MnG2Q-1smGJO2SPs-00cmj0; Thu, 27 Jun 2024 13:33:42 +0200 Message-ID: Date: Thu, 27 Jun 2024 13:33:40 +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 To: Ma Ke , dri-devel@lists.freedesktop.org, Daniel Vetter , Dave Airlie , Maarten Lankhorst , Maxime Ripard , Patrik Jakobsson , Thomas Zimmermann Cc: stable@vger.kernel.org, LKML , David Airlie References: <20240627063220.3013568-1-make24@iscas.ac.cn> Subject: Re: [PATCH v2] drm/gma500: fix null pointer dereference in cdv_intel_lvds_get_modes Content-Language: en-GB From: Markus Elfring In-Reply-To: <20240627063220.3013568-1-make24@iscas.ac.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:AOehDKKFPtxRHQPkx+LUzANkyLhTBUvzpw4KeRmCd3rgH5fsgxR 4hB57cBBQdjqt/ClaW4nBIog+T3Iadd5g5BlQPDYfJxlRtY3+TphaqUqIwXuOaBgcZa14VW vwMQmNT62qmSdaQH/4h5xTD/ZEE1kdLUYZy0U4cXKdxNpOEvVoz29cuP12WOzg9ha7023tX fSddlKToMHvRrbkMH+QbQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:JG+JqApF6Yc=;luGoJh8GDXk11DTuBXjZEvPBHkd ixtgHsNKOZX0DvF+p189t6tpAq8fTCFLkM8GQaKiPdUFZWMFof0C3W1dx4dARME4ukLKR1pe2 wbmQuRGMbppG3tKXuLIdgjWsi+hrNY2jWcCaIPOZgP++KRFWMc9Eub/Mku0q6s615bAEr2110 1UwtrJ8Gjf+Qc3Lqn6iLIb3XHp4JFPJgbsgXKiqsPtJQqsjTfJ1+aEimYnmfOdZeZLOHp3qtK FQr0o7xtcGnw3aVWWqi6GCbsdiCkVs0anW3WwRMkPuTWhWel0AkyAqvmyp9kq4i9of74nQNxM sDaHBQ4DwM4kgYJmVFh7RRiG2pnLL4c8ZPtbJkPzb+o8jCJkrEgz04YqGduIeUcbYobBwzL9v OjTm6hJ9QfnFQPi/De7zjiAaoAVnCwIMErYQOhdC4Kd8wt0wKl8bPybf5XDasS+r1l71oY2a/ Q07IBWEnaFWVp21tTOSVTbNMPdtNLkr/muzQ6dX20xAaRikGiz9zyheNOCyJBvLpx0icKW25m pGJLMGX9FzAVTlwVSVs8wwuCxHnQz+jsCOn32KEayKGbl5nHDDx5vxmX1KofAR6ECRrRIZNl9 IcOWdBnZsXkmCbpUPrQ2ICXhKFaMmx+IG+I+iZRyP8HFmlfxp4igmSX+fgVxXO4sjV1rgYl1H 2uj1VWk88o6zIzmXXo/cDNzmGNRWAKBVHv4Typ+M2Q87VMLqEmg07gQGDOpRd/sSXGDndx2/Z YLNCn2mvqiYNNvxZoiokcMSsOiltY5kEA/RnrJ7BwIEtRUj5b2KDPLP7WjWe1BL2U2SLLk+tr kI9ozjveIVyvrDXhppRPlI22vu5gyFjXudWSg+0FCqvjk= > In cdv_intel_lvds_get_modes(), the return value of drm_mode_duplicate() > is assigned to mode, which will lead to a NULL pointer dereference on > failure of drm_mode_duplicate(). Add a check to avoid npd. A) Can a wording approach (like the following) be a better change descript= ion? A null pointer is stored in the local variable =E2=80=9Cmode=E2=80=9D a= fter a call of the function =E2=80=9Cdrm_mode_duplicate=E2=80=9D failed. This point= er was passed to a subsequent call of the function =E2=80=9Cdrm_mode_probed_add=E2=80=9D= where an undesirable dereference will be performed then. Thus add a corresponding return value check. B) Would you like to append parentheses to the function name in the summary phrase? C) How do you think about to put similar results from static source code analyses into corresponding patch series? Regards, Markus