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 5DFF81758C; Tue, 25 Jun 2024 14:34:37 +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=1719326081; cv=none; b=H9uEObDl2kPP0LBOWrtuEkIsjkeUoyWkiBAt42HEvQwr6reIV+vcCMxYUG752tlRb9cX1cgVOxAs0q08CQOWNyaYWDLUPRkmJG7UKINUBs8z1V3PNgsEuNuJYMCoNR46XQN733GUVgEtK/yBlnp1kXpUYO4kyM94eWJnxUqII0U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719326081; c=relaxed/simple; bh=Kujgj0anIo/IcUOKduxF8pOvJsiKk1vmUd/L0ICVeTE=; h=Message-ID:Date:MIME-Version:To:Cc:References:Subject:From: In-Reply-To:Content-Type; b=Ttw91w0QWT5HlxmS7QPR0Jy0cofK1aVDzBCXUA5Gf9/Vodhsmg3rZ9akZzX8WoNgps2jBR6s6bJ/3lTeNMHdDbG1Ec/Cw74YUWRlqagwpX+YY/NkKABzLgKcoLVeA1CU97fxFpZaeWc8XDumAgLiauRbLFJe/G1Zs1leORwFIg8= 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=u7Fr9UsU; 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="u7Fr9UsU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=web.de; s=s29768273; t=1719326060; x=1719930860; i=markus.elfring@web.de; bh=4hqmfo5ctGH968xUb+z+rr8LiHMCJOdB3zcu6j3LRIo=; 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=u7Fr9UsU3M+6VBd5zDYTpRGJhqFvgvzY4YrzX23C5I6Lgp0KbH8vx9cc2MKyZNCp dkzT37MWVnNmUEpcdL076Ok7w7LDZVochztC4Ty3iBgmpD70AP8+ZXC9RpH6uPqu+ D+6Yk7PbqPZQPeUtuCCRyq7FJDub299czeluVijqPMelRaeXRE+zYx0obeXQiPA9B G6Pz5Xb1GnoHDYG71clPNaeyEb/HfpC8u8yaGsv20FSeyqlEVKg+E49m7YzwEuSBJ N3N4vo+0W6jFwDHR07KswcvJrxnwHdRHEkOiRn2s8TWg6NC3gw8SYEIjmcviicgh1 1JHYofBhbeDOo8I7bQ== X-UI-Sender-Class: 814a7b36-bfc1-4dae-8640-3722d8ec6cd6 Received: from [192.168.178.21] ([94.31.85.95]) by smtp.web.de (mrweb105 [213.165.67.124]) with ESMTPSA (Nemesis) id 1Mkmzl-1sl2f63wn1-00fa6K; Tue, 25 Jun 2024 16:34:20 +0200 Message-ID: Date: Tue, 25 Jun 2024 16:34:17 +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: <20240625081029.2619437-1-make24@iscas.ac.cn> Subject: Re: [PATCH] drm/nouveau/dispnv04: fix null pointer dereference in nv17_tv_get_hd_modes Content-Language: en-GB From: Markus Elfring In-Reply-To: <20240625081029.2619437-1-make24@iscas.ac.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:w+lKWxONvobVkG1JBjQ5wfxpvmogK7zfC3one7JxNJttL0yxtRT 2X3FNzQnbkxaLdb0QHQefzMbPsBUfPIZBpc17M3CtJkoxYSpCVRop7sRcgsds0cCrzG16JL 45sBtaD4ZQLCbci57s7tU6j4/EnczQZ9ldF89yqCNo7uLR/WEgR67k03y/u/VqbI+aIUgaR XzVzJnh9Z66x/b49M7tAg== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:trJvbE4vUhE=;eCQIKaNK/fS/KPnXOL1hOZwQ4wD 515WonsX5Vk7h9q7pmgwOtGWyFaCet7T6v+AZVm5PSUfqS7y6d3fAHfcUS7T4r0spc4lKcpPk wP2fRFk2qJIOfx3XYpHaUj1Un55DWZNBHbFcly+meblXwapr4wX2U2JdVDWOmlLIXIg7Wuwcu OWcjYmRKmZMrwUadiNtgncjLPE7cGJxQYexPcACsLCFeHoOnwcji81IVi6rKJ5DrMXlWMrKJU /tby3YQp5CgALY1vqtPIALu/vMtiLKVLsAJAVFHTpvBby15EaKO8hMCjtrMdnu9v8dBVIIizZ iVLSmdGiqTL6p36JQCxIw8O837C5lxTeIBeE09mAt/dZEuQvBC67JVyvS4z2IBozGt4Az9wIT 96RnxFazx5gaUlwa18DAS5UzJHqyrJxO7b867L3j5ysvCwFR9e10MIZemuHeYXwqUKoEj4K/f qP2DZhspPlq+Fs2CM+SG18tOdJdJ2vFnbXgDKguPRZUfVCT0C1wHmQi+iBO6k0uEUWOuPo7/v OLezWGdUCdUoebLnlGPp3DIORuJvVtYwnDzZe/lQGxOepiZvVSwTRsf2DC7Cm0QtlMcp7l+4X 8ofuF+uAqVlGK6h+HP3vXCxbBk1QB6lPnnRNeJbxSRXvQUCvfv3BJLmLzvHkVIiqZEowcJL29 b8ER3rE931Lxr9INbkCj/QBJnDKCzqjiNS283Sq3pQRYCkTY1kWUbNYH1EDY4gGOGK7d6mmd5 eSJ5B++ussY1vK6rfYjT4/El97/sTzSyq0aoJozgYil1SzQyTSgSj77jBEaWoRrHf9pl+nNuO CiRyhbn/PlOyELAV9EH2hhAa999Bw4yCLh6PEAK5a/8no= > In nv17_tv_get_hd_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(). The same applies to drm_cvt_mode(). > Add a check to avoid null pointer dereference. 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_cvt_mode=E2=80=9D or =E2=80=9Cdrm_mode_dupl= icate=E2=80=9D failed. This pointer was used in subsequent statements where an undesirable dereference will be performed then. Thus add corresponding return value checks. > 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 dereferences in nv17_tv_get_hd_modes()=E2=80= =9D? Regards, Markus