From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4749BCD5854 for ; Wed, 7 Jan 2026 11:12:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8FD8C10E051; Wed, 7 Jan 2026 11:12:42 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="JeNoit3p"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4262210E051 for ; Wed, 7 Jan 2026 11:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1767784359; bh=SIuRCY5B8G6/Y2yx+ABwBLAUOem5XagaWTiCtTcbOjc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JeNoit3p9aAFYtexMiWlGc1tcmle7WtaOqKBFi0v3JuFfssyZE4oC5T88IMM2NVgG l/D1z5XM7MZRkLULiv9YcVOqI0lId8FeKHheA30g7jsWcYnfygP8bVZnf+3qglMbZV xiJpbkyvWcK+TyPNrvYn9Wa1nPoMvQfj5SRKHlyDTGvCewfNFOvCq71apQpw0zHcQt 6q9FQdC/KbUYilLD6sJ+IUkn+g/3Gg41isoE+vDLms7yGcE7JYh2Y7rxIfWchukqVz UguqfIdPxCz45K/dfK1yxB8lubtfTHGvChGBRU1L2KWqmcpOxcZpcCeTu06Ium4JHb fN1hv1H0gsqRA== Received: from fedora (unknown [IPv6:2a01:e0a:2c:6930:d919:a6e:5ea1:8a9f]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 79D0617E1340; Wed, 7 Jan 2026 12:12:39 +0100 (CET) Date: Wed, 7 Jan 2026 12:12:32 +0100 From: Boris Brezillon To: dri-devel@lists.freedesktop.org, David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann Cc: kernel@collabora.com, =?UTF-8?B?TG/Dr2M=?= Molinari Subject: Re: [PATCH] drm/gem: Fix a GEM leak in drm_gem_get_unmapped_area() Message-ID: <20260107121232.6e1efae5@fedora> In-Reply-To: <20260106164935.409765-1-boris.brezillon@collabora.com> References: <20260106164935.409765-1-boris.brezillon@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, 6 Jan 2026 17:49:35 +0100 Boris Brezillon wrote: > drm_gem_object_lookup_at_offset() can return a valid object with > filp or filp->f_op->get_unmapped_area set to NULL. Make sure we still > release the ref we acquired on such objects. >=20 > Cc: Lo=C3=AFc Molinari > Fixes: 99bda20d6d4c ("drm/gem: Introduce drm_gem_get_unmapped_area() fop") > Signed-off-by: Boris Brezillon > --- > drivers/gpu/drm/drm_gem.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) >=20 > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index 36c8af123877..f7cbf6e8d1e0 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -1298,11 +1298,13 @@ unsigned long drm_gem_get_unmapped_area(struct fi= le *filp, unsigned long uaddr, > unsigned long ret; > =20 > obj =3D drm_gem_object_lookup_at_offset(filp, pgoff, len >> PAGE_SHIFT); > - if (IS_ERR(obj) || !obj->filp || !obj->filp->f_op->get_unmapped_area) > - return mm_get_unmapped_area(filp, uaddr, len, 0, flags); > + if (IS_ERR(obj)) > + obj =3D NULL; > =20 > - ret =3D obj->filp->f_op->get_unmapped_area(obj->filp, uaddr, len, 0, > - flags); > + if (!obj || !obj->filp || !obj->filp->f_op->get_unmapped_area) > + ret =3D mm_get_unmapped_area(filp, uaddr, len, 0, flags); Also, I'm wondering if we shouldn't pass pgoff instead of zero here to have the exact same behavior that existed before drm_gem_get_unmapped_area() was introduced. > + else > + ret =3D obj->filp->f_op->get_unmapped_area(obj->filp, uaddr, len, 0, f= lags); > =20 > drm_gem_object_put(obj); > =20