From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 318261494A8; Fri, 6 Dec 2024 14:57:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733497026; cv=none; b=XsPlW9JxCX1Go7X0kSPErlgtJAfhGZ8ohop7y1sdd1UQWsiXE/SWqJQs9Qsp58MScQ1w3mXxFrJ36/b0xdHLjy6IVTIYHIE1jkIRthEpCug9sGsBgLYY/CPq3lFjQkXr9gL2j2vT1KgzeqCYtADxyVGaZjNq6pO8qidqllYJNJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733497026; c=relaxed/simple; bh=ar5M2CtETQ7LffCerW3ynuKdBWAR7WQeSRU7nkmgto8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cuVjJ+2itQ9TlBLCPBmzypBtCoqWqXPB53CmlWENDhT8/56Lsa0EpdFviEZlkn3uQTua8wI9NvYGiI2HzLNn3dJlSpTGK5EACAb+hXC2KtBVNqVwFzjmZYhPi88l3Bv3/B8/9RypxUOiGiTqAU/uTE6GDhfCgFya7ve3yrO+IQM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zBqbfZ5P; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zBqbfZ5P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61A6AC4CED1; Fri, 6 Dec 2024 14:57:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733497026; bh=ar5M2CtETQ7LffCerW3ynuKdBWAR7WQeSRU7nkmgto8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zBqbfZ5PROHs+TemSLe0FA488cYrQZGBhSiL/PaBEEXbNZoLnic2WXmSzWB8xGo3F IDkta514cMDXpTR3VOdrXEYW0UiApIL3hfQMaPKJxXZR1DzoLNFNxGd2CE/jT39qLP A14wZXynqNs/3P1dHZUpKl7A0bgD0KeK+yoFA+hU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sebastian Reichel , Tomi Valkeinen , Sasha Levin Subject: [PATCH 6.6 171/676] drm/omap: Fix possible NULL dereference Date: Fri, 6 Dec 2024 15:29:50 +0100 Message-ID: <20241206143700.029903010@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143653.344873888@linuxfoundation.org> References: <20241206143653.344873888@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tomi Valkeinen [ Upstream commit a88fee2d67d9b78c24630a987a88ccf886b2498b ] smatch reports: drivers/gpu/drm/omapdrm/dss/base.c:176 omapdss_device_disconnect() error: we previously assumed 'src' could be null (see line 169) This code is mostly from a time when omapdrm had its own display device model. I can't honestly remember the details, and I don't think it's worth digging in deeply into that for a legacy driver. However, it looks like we only call omapdss_device_disconnect() and omapdss_device_connect() with NULL as the src parameter. We can thus drop the src parameter from both functions, and fix the smatch warning. I don't think omapdss_device_disconnect() ever gets NULL for the dst parameter (if it did, we'd crash soon after returning from the function), but I have kept the !dst check, just in case, but I added a WARN_ON() there. Also, if the dst parameter can be NULL, we can't always get the struct dss_device pointer from dst->dss (which is only used for a debug print). To make sure we can't hit that issue, do it similarly to the omapdss_device_connect() function: add 'struct dss_device *dss' as the first parameter, so that we always have it regardless of the dst. Fixes: 79107f274b2f ("drm/omap: Add support for drm_bridge") Reviewed-by: Sebastian Reichel Signed-off-by: Tomi Valkeinen Link: https://patchwork.freedesktop.org/patch/msgid/20240806-omapdrm-misc-fixes-v1-1-15d31aea0831@ideasonboard.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/omapdrm/dss/base.c | 25 ++++++------------------- drivers/gpu/drm/omapdrm/dss/omapdss.h | 3 +-- drivers/gpu/drm/omapdrm/omap_drv.c | 4 ++-- 3 files changed, 9 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/dss/base.c b/drivers/gpu/drm/omapdrm/dss/base.c index 050ca7eafac58..556e0f9026bed 100644 --- a/drivers/gpu/drm/omapdrm/dss/base.c +++ b/drivers/gpu/drm/omapdrm/dss/base.c @@ -139,21 +139,13 @@ static bool omapdss_device_is_connected(struct omap_dss_device *dssdev) } int omapdss_device_connect(struct dss_device *dss, - struct omap_dss_device *src, struct omap_dss_device *dst) { - dev_dbg(&dss->pdev->dev, "connect(%s, %s)\n", - src ? dev_name(src->dev) : "NULL", + dev_dbg(&dss->pdev->dev, "connect(%s)\n", dst ? dev_name(dst->dev) : "NULL"); - if (!dst) { - /* - * The destination is NULL when the source is connected to a - * bridge instead of a DSS device. Stop here, we will attach - * the bridge later when we will have a DRM encoder. - */ - return src && src->bridge ? 0 : -EINVAL; - } + if (!dst) + return -EINVAL; if (omapdss_device_is_connected(dst)) return -EBUSY; @@ -163,19 +155,14 @@ int omapdss_device_connect(struct dss_device *dss, return 0; } -void omapdss_device_disconnect(struct omap_dss_device *src, +void omapdss_device_disconnect(struct dss_device *dss, struct omap_dss_device *dst) { - struct dss_device *dss = src ? src->dss : dst->dss; - - dev_dbg(&dss->pdev->dev, "disconnect(%s, %s)\n", - src ? dev_name(src->dev) : "NULL", + dev_dbg(&dss->pdev->dev, "disconnect(%s)\n", dst ? dev_name(dst->dev) : "NULL"); - if (!dst) { - WARN_ON(!src->bridge); + if (WARN_ON(!dst)) return; - } if (!dst->id && !omapdss_device_is_connected(dst)) { WARN_ON(1); diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h index 040d5a3e33d68..4c22c09c93d52 100644 --- a/drivers/gpu/drm/omapdrm/dss/omapdss.h +++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h @@ -242,9 +242,8 @@ struct omap_dss_device *omapdss_device_get(struct omap_dss_device *dssdev); void omapdss_device_put(struct omap_dss_device *dssdev); struct omap_dss_device *omapdss_find_device_by_node(struct device_node *node); int omapdss_device_connect(struct dss_device *dss, - struct omap_dss_device *src, struct omap_dss_device *dst); -void omapdss_device_disconnect(struct omap_dss_device *src, +void omapdss_device_disconnect(struct dss_device *dss, struct omap_dss_device *dst); int omap_dss_get_num_overlay_managers(void); diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c index 21996b713d1c3..13790d3ac3b6a 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.c +++ b/drivers/gpu/drm/omapdrm/omap_drv.c @@ -307,7 +307,7 @@ static void omap_disconnect_pipelines(struct drm_device *ddev) for (i = 0; i < priv->num_pipes; i++) { struct omap_drm_pipeline *pipe = &priv->pipes[i]; - omapdss_device_disconnect(NULL, pipe->output); + omapdss_device_disconnect(priv->dss, pipe->output); omapdss_device_put(pipe->output); pipe->output = NULL; @@ -325,7 +325,7 @@ static int omap_connect_pipelines(struct drm_device *ddev) int r; for_each_dss_output(output) { - r = omapdss_device_connect(priv->dss, NULL, output); + r = omapdss_device_connect(priv->dss, output); if (r == -EPROBE_DEFER) { omapdss_device_put(output); return r; -- 2.43.0