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 CA9CAC55196 for ; Mon, 3 Aug 2026 18:35:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2A9E510E098; Mon, 3 Aug 2026 18:35:03 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="ZIn7DATT"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id CB43A10E098 for ; Mon, 3 Aug 2026 18:35:01 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 7235842B6E; Mon, 3 Aug 2026 18:35:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 044E41F00A3D; Mon, 3 Aug 2026 18:35:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785782101; bh=56dAQEl/uWsg2t/erpRYymTDZhcEWsarYH0GDBKSWtA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ZIn7DATTcAA5pLYQavX33/o47O7vxRkp8KXGugRlaI7emd0H8f7FaXtP5v3qdEony xI2OOpc5+x/FtnksFzWWVgqt13how3VTlbN12SCLL7dYs7theiiEhWJASQlt7x6T1O 3ZXPSB6dJ6O8V6+XgOv2xSuhU5N/AFV5Sa5E2tMYbGKxdx/cQ3YgpHBZw5hYcyvPW2 Tv7k1YzQME0kJXyFlzz5we8ZhF9AaFqdemsvPZ50O+KUdB0U1CnWW0FwiJA7rl9cua 4RHW09NFYaeIjpUS6mOHqRqQNC6E0yTR6VsHYVdk0ls/ky+W3kDZgAO3LM0d7CR3fG gHSgF2KeiA0jQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v9 09/22] drm/bridge: synopsys: dw-dp: Free output_fmts when none are valid To: "Sebastian Reichel" Cc: conor+dt@kernel.org, dri-devel@lists.freedesktop.org, robh@kernel.org, devicetree@vger.kernel.org In-Reply-To: <20260803-synopsys-dw-dp-improvements-v9-9-2e6e46135312@collabora.com> References: <20260803-synopsys-dw-dp-improvements-v9-0-2e6e46135312@collabora.com> <20260803-synopsys-dw-dp-improvements-v9-9-2e6e46135312@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 03 Aug 2026 18:35:00 +0000 Message-Id: <20260803183501.044E41F00A3D@smtp.kernel.org> 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: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] The DRM core's bridge bus format negotiation protocol contains a m= emory leak when a driver returns an allocated format array but 0 valid form= ats. This problem wasn't introduced by this patch, but this patch adds a dr= iver-local workaround instead of fixing the core API. -- --- Patch [9]: [PATCH v9 09/22] drm/bridge: synopsys: dw-dp: Free output_fm= ts when none are valid --- commit 91ba4a99e0fef78bbe1a7632011fef0a483a9e57 Author: Sebastian Reichel drm/bridge: synopsys: dw-dp: Free output_fmts when none are valid This commit modifies dw_dp_bridge_atomic_get_output_bus_fmts() to free the allocated output_fmts array if the number of valid formats is 0, avoiding a memory leak. > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/br= idge/synopsys/dw-dp.c > index 22a244de08aa1..bde938b0d116d 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c > @@ -1813,6 +1813,11 @@ static u32 *dw_dp_bridge_atomic_get_output_bus_fmt= s(struct drm_bridge *bridge, > output_fmts[j++] =3D fmt->bus_format; > } > =20 > + if (j =3D=3D 0) { > + kfree(output_fmts); > + output_fmts =3D NULL; > + } > + [Severity: High] This isn't a bug introduced by this patch, but should this memory leak be fixed in the DRM core instead of adding a driver-local workaround? Looking at the DRM core's bridge bus format negotiation protocol in drivers/gpu/drm/drm_bridge.c, the core leaks the array when a driver returns an allocated format array but 0 valid formats: drivers/gpu/drm/drm_bridge.c:drm_atomic_bridge_chain_select_bus_fmts() { ... out_bus_fmts =3D funcs->atomic_get_output_bus_fmts(last_bridge, last_bridge_state, crtc_state, conn_state, &num_out_bus_fmts); if (!num_out_bus_fmts) return -ENOTSUPP; ... } The core returns an error immediately without calling kfree(out_bus_fmts), silently leaking the dynamically allocated array. The same issue appears in select_bus_fmt_recursive() for atomic_get_input_bus_fmts: drivers/gpu/drm/drm_bridge.c:select_bus_fmt_recursive() { ... in_bus_fmts =3D cur_bridge->funcs->atomic_get_input_bus_fmts(cur_bridge, cur_state, crtc_state, conn_state, out_bus_fmt, &num_in_bus_fmts); if (!num_in_bus_fmts) return -ENOTSUPP; ... } Would it be better to fix the core API to handle freeing the array when num_out_bus_fmts or num_in_bus_fmts is 0, rather than patching each individual bridge driver? > *num_output_fmts =3D j; > =20 > return output_fmts; --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260803-synopsys-d= w-dp-improvements-v9-0-2e6e46135312@collabora.com?part=3D9