ltdc_load() calls functions drm_crtc_init_with_planes() and drm_universal_plane_init(). These functions should not be called with parameters allocated with devm_kzalloc() to avoid use-after-free issues [1].
The patch replaces managed resource allocations with regular ones. Found by Linux Verification Center (linuxtesting.org). [1] https://lore.kernel.org/lkml/u366i76e3qhh3ra5oxrtngjtm2u5lterkekcz6y2jkndhuxzli@diujon4h7qwb/ Signed-off-by: Katya Orlova <[email protected]> --- drivers/gpu/drm/stm/drv.c | 11 ++++-- drivers/gpu/drm/stm/ltdc.c | 72 ++++++++++++++++++++++++++------------ 2 files changed, 58 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c index cb4404b3ce62..409f26d3e400 100644 --- a/drivers/gpu/drm/stm/drv.c +++ b/drivers/gpu/drm/stm/drv.c @@ -74,7 +74,7 @@ static int drv_load(struct drm_device *ddev) DRM_DEBUG("%s\n", __func__); - ldev = devm_kzalloc(ddev->dev, sizeof(*ldev), GFP_KERNEL); + ldev = kzalloc(sizeof(*ldev), GFP_KERNEL); if (!ldev) return -ENOMEM; @@ -82,7 +82,7 @@ static int drv_load(struct drm_device *ddev) ret = drmm_mode_config_init(ddev); if (ret) - return ret; + goto err; /* * set max width and height as default value. @@ -98,7 +98,7 @@ static int drv_load(struct drm_device *ddev) ret = ltdc_load(ddev); if (ret) - return ret; + goto err; drm_mode_config_reset(ddev); drm_kms_helper_poll_init(ddev); @@ -106,6 +106,9 @@ static int drv_load(struct drm_device *ddev) platform_set_drvdata(pdev, ddev); return 0; +err: + kfree(ldev); + return ret; } static void drv_unload(struct drm_device *ddev) @@ -114,6 +117,8 @@ static void drv_unload(struct drm_device *ddev) drm_kms_helper_poll_fini(ddev); ltdc_unload(ddev); + kfree(ddev->dev_private); + ddev->dev_private = NULL; } static __maybe_unused int drv_suspend(struct device *dev) diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index b8be4c1db423..ec3bc3637a63 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -1120,6 +1120,12 @@ static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = { .get_scanout_position = ltdc_crtc_get_scanout_position, }; +static void ltdc_crtc_destroy(struct drm_crtc *crtc) +{ + drm_crtc_cleanup(crtc); + kfree(crtc); +} + static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc) { struct ltdc_device *ldev = crtc_to_ltdc(crtc); @@ -1200,7 +1206,7 @@ static void ltdc_crtc_atomic_print_state(struct drm_printer *p, } static const struct drm_crtc_funcs ltdc_crtc_funcs = { - .destroy = drm_crtc_cleanup, + .destroy = ltdc_crtc_destroy, .set_config = drm_atomic_helper_set_config, .page_flip = drm_atomic_helper_page_flip, .reset = drm_atomic_helper_crtc_reset, @@ -1213,7 +1219,7 @@ 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, + .destroy = ltdc_crtc_destroy, .set_config = drm_atomic_helper_set_config, .page_flip = drm_atomic_helper_page_flip, .reset = drm_atomic_helper_crtc_reset, @@ -1543,10 +1549,16 @@ static void ltdc_plane_atomic_print_state(struct drm_printer *p, fpsi->counter = 0; } +static void ltdc_plane_destroy(struct drm_plane *plane) +{ + drm_plane_cleanup(plane); + kfree(plane); +} + 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, + .destroy = ltdc_plane_destroy, .reset = drm_atomic_helper_plane_reset, .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state, .atomic_destroy_state = drm_atomic_helper_plane_destroy_state, @@ -1565,7 +1577,6 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev, { unsigned long possible_crtcs = CRTC_MASK; struct ltdc_device *ldev = ddev->dev_private; - struct device *dev = ddev->dev; struct drm_plane *plane; unsigned int i, nb_fmt = 0; u32 *formats; @@ -1576,7 +1587,7 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev, int ret; /* Allocate the biggest size according to supported color formats */ - formats = devm_kzalloc(dev, (ldev->caps.pix_fmt_nb + + formats = kzalloc((ldev->caps.pix_fmt_nb + ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp) + ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp) + ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp)) * @@ -1614,15 +1625,20 @@ static struct drm_plane *ltdc_plane_create(struct drm_device *ddev, } } - plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL); - if (!plane) + plane = kzalloc(sizeof(*plane), GFP_KERNEL); + if (!plane) { + kfree(formats); return NULL; + } ret = drm_universal_plane_init(ddev, plane, possible_crtcs, <dc_plane_funcs, formats, nb_fmt, modifiers, type, NULL); - if (ret < 0) + kfree(formats); + if (ret < 0) { + kfree(plane); return NULL; + } if (ldev->caps.ycbcr_input) { if (val & (LXCR_C1R_YIA | LXCR_C1R_YSPA | LXCR_C1R_YFPA)) @@ -1650,7 +1666,7 @@ static void ltdc_plane_destroy_all(struct drm_device *ddev) list_for_each_entry_safe(plane, plane_temp, &ddev->mode_config.plane_list, head) - drm_plane_cleanup(plane); + ltdc_plane_destroy(plane); } static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc) @@ -1936,7 +1952,7 @@ int ltdc_load(struct drm_device *ddev) if (!nb_endpoints) return -ENODEV; - ldev->pixel_clk = devm_clk_get(dev, "lcd"); + ldev->pixel_clk = clk_get(dev, "lcd"); if (IS_ERR(ldev->pixel_clk)) { if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER) DRM_ERROR("Unable to get lcd clock\n"); @@ -1982,7 +1998,7 @@ int ltdc_load(struct drm_device *ddev) } } - rstc = devm_reset_control_get_exclusive(dev, NULL); + rstc = reset_control_get_exclusive(dev, NULL); mutex_init(&ldev->err_lock); @@ -1993,25 +2009,25 @@ int ltdc_load(struct drm_device *ddev) } res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - ldev->regs = devm_ioremap_resource(dev, res); + ldev->regs = ioremap(res->start, resource_size(res)); if (IS_ERR(ldev->regs)) { DRM_ERROR("Unable to get ltdc registers\n"); ret = PTR_ERR(ldev->regs); goto err; } - ldev->regmap = devm_regmap_init_mmio(&pdev->dev, ldev->regs, &stm32_ltdc_regmap_cfg); + ldev->regmap = regmap_init_mmio(&pdev->dev, ldev->regs, &stm32_ltdc_regmap_cfg); if (IS_ERR(ldev->regmap)) { DRM_ERROR("Unable to regmap ltdc registers\n"); ret = PTR_ERR(ldev->regmap); - goto err; + goto err_iounmap; } ret = ltdc_get_caps(ddev); if (ret) { DRM_ERROR("hardware identifier (0x%08x) not supported!\n", ldev->caps.hw_version); - goto err; + goto err_regmap_exit; } /* Disable interrupts */ @@ -2034,49 +2050,57 @@ int ltdc_load(struct drm_device *ddev) irq = platform_get_irq(pdev, i); if (irq < 0) { ret = irq; - goto err; + goto err_regmap_exit; } - ret = devm_request_threaded_irq(dev, irq, ltdc_irq, + ret = request_threaded_irq(irq, ltdc_irq, ltdc_irq_thread, IRQF_ONESHOT, dev_name(dev), ddev); if (ret) { DRM_ERROR("Failed to register LTDC interrupt\n"); - goto err; + goto err_regmap_exit; } } - crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL); + crtc = kzalloc(sizeof(*crtc), GFP_KERNEL); if (!crtc) { DRM_ERROR("Failed to allocate crtc\n"); ret = -ENOMEM; - goto err; + goto err_regmap_exit; } ret = ltdc_crtc_init(ddev, crtc); if (ret) { DRM_ERROR("Failed to init crtc\n"); - goto err; + goto free_crtc; } ret = drm_vblank_init(ddev, NB_CRTC); if (ret) { DRM_ERROR("Failed calling drm_vblank_init()\n"); - goto err; + goto free_crtc; } clk_disable_unprepare(ldev->pixel_clk); + clk_put(ldev->pixel_clk); pinctrl_pm_select_sleep_state(ddev->dev); pm_runtime_enable(ddev->dev); return 0; +free_crtc: + kfree(crtc); +err_regmap_exit: + regmap_exit(ldev->regmap); +err_iounmap: + iounmap(ldev->regs); 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); + clk_put(ldev->pixel_clk); return ret; } @@ -2084,6 +2108,7 @@ int ltdc_load(struct drm_device *ddev) void ltdc_unload(struct drm_device *ddev) { struct device *dev = ddev->dev; + struct ltdc_device *ldev = ddev->dev_private; int nb_endpoints, i; DRM_DEBUG_DRIVER("\n"); @@ -2094,6 +2119,9 @@ void ltdc_unload(struct drm_device *ddev) drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i); pm_runtime_disable(ddev->dev); + + regmap_exit(ldev->regmap); + iounmap(ldev->regs); } MODULE_AUTHOR("Philippe Cornu <[email protected]>"); -- 2.30.2
