[PATCH OLK-6.6] drm/stm: Avoid use-after-free issues with crtc and plane

25 Oct 2024

From: Katya Orlova e.orlova@ispras.ru
stable inclusion
from stable-v6.6.55
commit 0a1741d10da29aa84955ef89ae9a03c4b6038657
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRAF
CVE: CVE-2024-49992
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit 19dd9780b7ac673be95bf6fd6892a184c9db611f ]
ltdc_load() calls functions drm_crtc_init_with_planes(),
drm_universal_plane_init() and drm_encoder_init(). These functions
should not be called with parameters allocated with devm_kzalloc()
to avoid use-after-free issues [1].
Use allocations managed by the DRM framework.
Found by Linux Verification Center (linuxtesting.org).
[1]
https://lore.kernel.org/lkml/u366i76e3qhh3ra5oxrtngjtm2u5lterkekcz6y2jkndhux...
Signed-off-by: Katya Orlova e.orlova@ispras.ru
Acked-by: Raphaël Gallais-Pou raphael.gallais-pou@foss.st.com
Link: https://patchwork.freedesktop.org/patch/msgid/20240216125040.8968-1-e.orlova...
Signed-off-by: Raphael Gallais-Pou raphael.gallais-pou@foss.st.com
Signed-off-by: Sasha Levin sashal@kernel.org
Conflicts:
        drivers/gpu/drm/stm/drv.c
        drivers/gpu/drm/stm/ltdc.c
[ context conflicts. ]
Signed-off-by: Zhang Kunbo zhangkunbo@huawei.com
---
 drivers/gpu/drm/stm/drv.c  |  3 +-
 drivers/gpu/drm/stm/ltdc.c | 73 ++++++++++----------------------------
 2 files changed, 20 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
index e8523abef27a..152bec2c0238 100644
--- a/drivers/gpu/drm/stm/drv.c
+++ b/drivers/gpu/drm/stm/drv.c
@@ -25,6 +25,7 @@
 #include <drm/drm_module.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_managed.h>
#include "ltdc.h"
@@ -75,7 +76,7 @@ static int drv_load(struct drm_device *ddev)
DRM_DEBUG("%s\n", __func__);
-	ldev = devm_kzalloc(ddev->dev, sizeof(*ldev), GFP_KERNEL);
+	ldev = drmm_kzalloc(ddev, sizeof(*ldev), GFP_KERNEL);
    if (!ldev)
    	return -ENOMEM;
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 5576fdae4962..eeaabb4e10d3 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -36,6 +36,7 @@
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
 #include <drm/drm_vblank.h>
+#include <drm/drm_managed.h>
#include <video/videomode.h>
@@ -1199,7 +1200,6 @@ static void ltdc_crtc_atomic_print_state(struct drm_printer *p,
 }
static const struct drm_crtc_funcs ltdc_crtc_funcs = {
-	.destroy = drm_crtc_cleanup,
    .set_config = drm_atomic_helper_set_config,
    .page_flip = drm_atomic_helper_page_flip,
    .reset = drm_atomic_helper_crtc_reset,
@@ -1212,7 +1212,6 @@ static const struct drm_crtc_funcs ltdc_crtc_funcs = {
 };
static const struct drm_crtc_funcs ltdc_crtc_with_crc_support_funcs = {
-	.destroy = drm_crtc_cleanup,
    .set_config = drm_atomic_helper_set_config,
    .page_flip = drm_atomic_helper_page_flip,
    .reset = drm_atomic_helper_crtc_reset,
@@ -1545,7 +1544,6 @@ static void ltdc_plane_atomic_print_state(struct drm_printer *p,
 static const struct drm_plane_funcs ltdc_plane_funcs = {
    .update_plane = drm_atomic_helper_update_plane,
    .disable_plane = drm_atomic_helper_disable_plane,
-	.destroy = drm_plane_cleanup,
    .reset = drm_atomic_helper_plane_reset,
    .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
    .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
@@ -1572,7 +1570,6 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
    const u64 *modifiers = ltdc_format_modifiers;
    u32 lofs = index * LAY_OFS;
    u32 val;
-	int ret;
/* Allocate the biggest size according to supported color formats */
    formats = devm_kzalloc(dev, (ldev->caps.pix_fmt_nb +
@@ -1613,14 +1610,10 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
    	}
    }
-	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
-	if (!plane)
-		return NULL;
-
-	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
-				       &ltdc_plane_funcs, formats, nb_fmt,
-				       modifiers, type, NULL);
-	if (ret < 0)
+	plane = drmm_universal_plane_alloc(ddev, struct drm_plane, dev,
+					   possible_crtcs, &ltdc_plane_funcs, formats,
+					   nb_fmt, modifiers, type, NULL);
+	if (IS_ERR(plane))
    	return NULL;
if (ldev->caps.ycbcr_input) {
@@ -1643,15 +1636,6 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
    return plane;
 }
-static void ltdc_plane_destroy_all(struct drm_device *ddev)
-{
-	struct drm_plane *plane, *plane_temp;
-
-	list_for_each_entry_safe(plane, plane_temp,
-				 &ddev->mode_config.plane_list, head)
-		drm_plane_cleanup(plane);
-}
-
 static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
 {
    struct ltdc_device *ldev = ddev->dev_private;
@@ -1677,14 +1661,14 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
/* Init CRTC according to its hardware features */
    if (ldev->caps.crc)
-		ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
-						&ltdc_crtc_with_crc_support_funcs, NULL);
+		ret = drmm_crtc_init_with_planes(ddev, crtc, primary, NULL,
+						 &ltdc_crtc_with_crc_support_funcs, NULL);
    else
-		ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
-						&ltdc_crtc_funcs, NULL);
+		ret = drmm_crtc_init_with_planes(ddev, crtc, primary, NULL,
+						 &ltdc_crtc_funcs, NULL);
    if (ret) {
    	DRM_ERROR("Can not initialize CRTC\n");
-		goto cleanup;
+		return ret;
    }
drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
@@ -1698,9 +1682,8 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
    for (i = 1; i < ldev->caps.nb_layers; i++) {
    	overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY, i);
    	if (!overlay) {
-			ret = -ENOMEM;
    		DRM_ERROR("Can not create overlay plane %d\n", i);
-			goto cleanup;
+			return -ENOMEM;
    	}
    	if (ldev->caps.dynamic_zorder)
    		drm_plane_create_zpos_property(overlay, i, 0, ldev->caps.nb_layers - 1);
@@ -1713,10 +1696,6 @@ static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
    }
return 0;
-
-cleanup:
-	ltdc_plane_destroy_all(ddev);
-	return ret;
 }
static void ltdc_encoder_disable(struct drm_encoder *encoder)
@@ -1776,23 +1755,19 @@ static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
    struct drm_encoder *encoder;
    int ret;
-	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
-	if (!encoder)
-		return -ENOMEM;
+	encoder = drmm_simple_encoder_alloc(ddev, struct drm_encoder, dev,
+					    DRM_MODE_ENCODER_DPI);
+	if (IS_ERR(encoder))
+		return PTR_ERR(encoder);
encoder->possible_crtcs = CRTC_MASK;
    encoder->possible_clones = 0;	/* No cloning support */
-	drm_simple_encoder_init(ddev, encoder, DRM_MODE_ENCODER_DPI);
-
    drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);
ret = drm_bridge_attach(encoder, bridge, NULL, 0);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			drm_encoder_cleanup(encoder);
+	if (ret)
    	return ret;
-	}
DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
@@ -1962,8 +1937,7 @@ int ltdc_load(struct drm_device *ddev)
    		goto err;
if (panel) {
-			bridge = drm_panel_bridge_add_typed(panel,
-							    DRM_MODE_CONNECTOR_DPI);
+			bridge = drmm_panel_bridge_add(ddev, panel);
    		if (IS_ERR(bridge)) {
    			DRM_ERROR("panel-bridge endpoint %d\n", i);
    			ret = PTR_ERR(bridge);
@@ -2045,7 +2019,7 @@ int ltdc_load(struct drm_device *ddev)
    	}
    }
-	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
+	crtc = drmm_kzalloc(ddev, sizeof(*crtc), GFP_KERNEL);
    if (!crtc) {
    	DRM_ERROR("Failed to allocate crtc\n");
    	ret = -ENOMEM;
@@ -2072,9 +2046,6 @@ int ltdc_load(struct drm_device *ddev)
return 0;
 err:
-	for (i = 0; i < nb_endpoints; i++)
-		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
-
    clk_disable_unprepare(ldev->pixel_clk);
return ret;
@@ -2082,16 +2053,8 @@ int ltdc_load(struct drm_device *ddev)
void ltdc_unload(struct drm_device *ddev)
 {
-	struct device *dev = ddev->dev;
-	int nb_endpoints, i;
-
    DRM_DEBUG_DRIVER("\n");
-	nb_endpoints = of_graph_get_endpoint_count(dev->of_node);
-
-	for (i = 0; i < nb_endpoints; i++)
-		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);
-
    pm_runtime_disable(ddev->dev);
 }
-- 
2.34.1


    

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[PATCH OLK-6.6] drm/stm: Avoid use-after-free issues with crtc and plane