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 E3639CCD193 for ; Mon, 20 Oct 2025 11:20:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4593D10E288; Mon, 20 Oct 2025 11:20:10 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="MaMM1T8k"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id 496AF10E288 for ; Mon, 20 Oct 2025 11:20:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1760959206; bh=GbM499rYztmTo2pv+FqowS2W/5GxpHh/TTTctifhzfo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MaMM1T8k1/m2rJf1LXKMv2d2M8wMTD7/cJiEuzXtHLTudXpOZj6/9Tt1da9Ga1OUJ Dq776rdaXYJZDKpK4RuEJgkdjg+Pyn4wyzItHcv4GA5ZWM+WfTLjWuLeKdWmFL9bgw xgAEM9r9Ku9D23mQ3ZYGhgzmnnRXdXzdH6MYfG2v1Ls+Dejsf6A/iYMZmHAl4YyilR 5nqu38/DlwHGBke2SXUc4sLBSajJ86AZBKVF5KjrTvTjIq6jjo+2K9t1ogg0hxAw1l RBYw24x6oj06R520r8Eo78QAAJDO5XAcwkJLQH5VIyzNTQdc83P16h0T9yYFVL04Ux GwQHs/ZbBkvZw== 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 X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 5E74A17E129E; Mon, 20 Oct 2025 13:20:06 +0200 (CEST) Date: Mon, 20 Oct 2025 13:20:01 +0200 From: Boris Brezillon To: Akash Goel Cc: liviu.dudau@arm.com, steven.price@arm.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, nd@arm.com Subject: Re: [PATCH] drm/panthor: Fix potential memleak of vma structure Message-ID: <20251020132001.75ac7598@fedora> In-Reply-To: <6549faee-1633-427a-b7e8-3722808976f2@arm.com> References: <20251020085914.1276090-1-akash.goel@arm.com> <20251020113029.1ec51806@fedora> <6549faee-1633-427a-b7e8-3722808976f2@arm.com> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 Mon, 20 Oct 2025 10:50:19 +0100 Akash Goel wrote: > On 10/20/25 10:30, Boris Brezillon wrote: > > On Mon, 20 Oct 2025 09:59:14 +0100 > > Akash Goel wrote: > > > >> This commit addresses a memleak issue of panthor_vma (or drm_gpuva) > >> structure in Panthor driver, that can happen if the GPU page table > >> update operation to map the pages fail. > >> The issue is very unlikely to occur in practice. > >> > >> Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") > >> Signed-off-by: Akash Goel > >> --- > >> drivers/gpu/drm/panthor/panthor_mmu.c | 4 +++- > >> 1 file changed, 3 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > >> index 6dec4354e378..34a86f7b58d9 100644 > >> --- a/drivers/gpu/drm/panthor/panthor_mmu.c > >> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > >> @@ -2081,8 +2081,10 @@ static int panthor_gpuva_sm_step_map(struct drm_gpuva_op *op, void *priv) > >> ret = panthor_vm_map_pages(vm, op->map.va.addr, flags_to_prot(vma->flags), > >> op_ctx->map.sgt, op->map.gem.offset, > >> op->map.va.range); > >> - if (ret) > >> + if (ret) { > >> + kfree(vma); > > > > Calling kfree() in this context is probably fine, but I think I'd > > prefer if we were introducing a panthor_vm_op_ctx_return_vma() helper > > returning the vma to the preallocated array, and letting the deferred > > cleanup function free this up. > > > Thanks for the quick review. > > So need to do like this, where we search for a NULL entry to store the > VMA pointer to be returned ? > > static void > panthor_vm_op_ctx_return_vma(struct panthor_vm_op_ctx *op_ctx, > struct panthor_vma *vma) > { > for (u32 i = 0; i < ARRAY_SIZE(op_ctx->preallocated_vmas); i++) { > if (!op_ctx->preallocated_vmas[i]) { > op_ctx->preallocated_vmas[i] = vma; > return; > } > } > } > > > Please let me know. Yep, that looks good to me.