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 DEAE815FA67; Tue, 25 Jun 2024 13:44:05 +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=1719323048; cv=none; b=GZCFU5hvt8R1Um0QoVTp9MKa+Z2zQnXK08QLiZTZQ6Ou2XKWPcnzgkza+ILGLn7w1NfgTIKScddyguOZ6X1uFzOCQnjsmkhaA8Zl0W1brSjbX5XQX+24VdGzAiOodjpdnNEwyI8opXmdEU6+1C3uub6rmSUREoaTpX+NxHVpvxE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719323048; c=relaxed/simple; bh=nQof8rcMNrS5cmjQ+nkn595vum50vVtm/h/QsH2E8fM=; h=Message-ID:Date:MIME-Version:To:Cc:References:Subject:From: In-Reply-To:Content-Type; b=J+QAjPd+WErNpJrnlnM6RT+BaK+nunJSm3Q0Pha9xF6YuQ7k/ohCsD8N1gOvVGLGkzDCyG/YmosVcKC5IZRlloAON0PWhd5/G2+rowPTia8Dhd9ZH158goEDEU1Yqq7ZvoPAPJl7okl9N8eO7Rl/9UeikdJqEFFNKjvE/qVYYls= 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=JZtLw47+; 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="JZtLw47+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=web.de; s=s29768273; t=1719323019; x=1719927819; i=markus.elfring@web.de; bh=DW1LoQxnS5f5LRrDsRgHA085uas+2Iji0oND03zB5nw=; 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=JZtLw47+8ZyxUQil47G0W9CULuQE+/JfNdpxAWvPwO4MAdZGujO9q9ZLMc8pZUsq 8dT5qM08y4b+8tg0bJfgPWZhQU3HC1Z0eIarKnMEtuphSCvFEvHILuhd/hR3y8QDq aZl1Vto3FAg+Tt7+rHw0pL6WXGKCV7allTAHdPIKI20Od5oWPiucLMLedhBNKpRGl Cnw86c5noH+bom6O86Rq/oseOUbYM7mnXhj4aO2qyJ0pD4jBCD2K26+E9D8IAXasX 77N1Tlyt0tZNGrCcqoeVGIl3TB1MBA8Q3Iud0KOQophl0EJAQTX+MMnJkdzYK6NWo ahwsti5odAruw0244w== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Received: from [192.168.178.21] ([94.31.85.95]) by smtp.web.de (mrweb106 [213.165.67.124]) with ESMTPSA (Nemesis) id 1Ml4B4-1slIGt03yO-00aZqS; Tue, 25 Jun 2024 15:43:39 +0200 Message-ID: <8517da06-3010-4356-b5df-d9a14454feec@web.de> Date: Tue, 25 Jun 2024 15:43:37 +0200 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Ma Ke , nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Daniel Vetter , Danilo Krummrich , David Airlie , Karol Herbst , Lyude Paul Cc: stable@vger.kernel.org, LKML References: <20240625081828.2620794-1-make24@iscas.ac.cn> Subject: Re: [PATCH] drm/nouveau/dispnv04: fix null pointer dereference in nv17_tv_get_ld_modes Content-Language: en-GB From: Markus Elfring In-Reply-To: <20240625081828.2620794-1-make24@iscas.ac.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:8F+pc+WjJBMs7OzY5IXr8xjes+NHPd6uUM/JgMMrj0JM3JjYtro 7+xVBXbK1BB3qzpe8Vj63qlrfX6Iz4XB4uAaeID6Oi6sX/8dwbygMeWaU8XJd5zmjv7wvhz HbdjafVWM8k8//vuS5mQ8TqHrsP5E3LxNsv8fZJtil7uYGTVby9/NkoOGZ68Rdt1J80WzRg rI+Ddk6GAKKeXXlYhzf2Q== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:UFhOZZ2eABg=;aZuRWvDiFzEGW8Ba2s44hN220sC Gh24rZ7uhloY3U1kRDLb1bj3kxglyTcH2SzKcb63zeF9DrpELlVQs74PzIi0DTQMKqETyC1x/ A/ZR6Z1s1X80DPDTbWZNHuu1stccBrSg16ByR5cnNzbubMOd10Wj6xrkPatWpcyesm85DFdci hWqcnPAU26WwTvUGcFeNre4DWx7u+/Kzlne6/mmFz88v9k5H/eIFW/byTObUixhWEweafb5Dr iGMs+NUHYv5bRwRFsmOXrx5VinQD1sFyes9brzw9VhHSK6S8ayNQt9HQdYAmruGurxBNiySo3 GoaUMbD880Pa8rOMxyEnnlZUjx9y61q9sVT0ByFTm9GPRIZKi1O5Z6a4021dBassSlp5DGDYa 0Qcl1YAQPG+TspeMG2yniEQgXWzQ7kBo2yas0Vnm8NaryHdPri0HmiSpUKWJ0c5j0PPzkZgN1 rM0Jr1MbiENq2E/MDbYZlz26A0NrR4ConxomQz72+nTwhUCaNcDxFMY0fdHxcTe8LkWpuZ6BG yMjlxYPIzUiS18kSrHV7iVPn/xBVsQMDoPWAF2qLpSiN16QXKr2NBk/S2eeOkuudaPc+xxF4V IcMlrb57nadyFv+smgIwXDbxp6bA+Eh2oergs38lwk3ovBAW5dPpMtYzm3pjOF0IBA/Kt/IWH LTlntl3lrQZxtj6wgiGL+oeK80uxjXVA1TiDEJcO1Om6sudghNwirfZ280uKovxElkjlOZi9n 1UB993xA+H//Zig609Ut/fAnVz3N+ffZTLt3Cyh2TuP6LsNx3jWeuey3OSi9Uwf4Ab/3ljbdn MzjLGUYSMU3TfsrQ4QhQ7ToqOjZOA7jwwdofEuIbRTRV0= > In nv17_tv_get_ld_modes(), the return value of drm_mode_duplicate() is > assigned to mode, which will lead to a possible NULL pointer dereference > on failure of drm_mode_duplicate(). Add a check to avoid npd. Can a wording approach (like the following) be a better change description= ? A null pointer is stored in the local variable =E2=80=9Cmode=E2=80=9D af= ter a call of the function =E2=80=9Cdrm_mode_duplicate=E2=80=9D failed. This pointe= r was used in a subsequent statement where an undesirable dereference will be performed then. Thus add a corresponding return value check. > Cc: stable@vger.kernel.org Would you like to add the tag =E2=80=9CFixes=E2=80=9D accordingly? How do you think about to use a summary phrase like =E2=80=9CPrevent null pointer dereference in nv17_tv_get_ld_modes()=E2=80= =9D? Regards, Markus