From 7f0ba8f98a4ec3bee6a5d612e676a75791c0f127 Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Mon, 11 Jul 2022 19:38:55 +0200 Subject: [PATCH] drm/vc4: dpi: Switch to drmm_kzalloc Our internal structure that stores the DRM entities structure is allocated through a device-managed kzalloc. This means that this will eventually be freed whenever the device is removed. In our case, the most likely source of removal is that the main device is going to be unbound, and component_unbind_all() is being run. However, it occurs while the DRM device is still registered, which will create dangling pointers, eventually resulting in use-after-free. Switch to a DRM-managed allocation to keep our structure until the DRM driver doesn't need it anymore. Acked-by: Thomas Zimmermann Reviewed-by: Dave Stevenson Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220711173939.1132294-26-maxime@cerno.tech --- drivers/gpu/drm/vc4/vc4_dpi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c index 7c4bfbd7ed9f..7a1112c12be4 100644 --- a/drivers/gpu/drm/vc4/vc4_dpi.c +++ b/drivers/gpu/drm/vc4/vc4_dpi.c @@ -264,9 +264,10 @@ static int vc4_dpi_bind(struct device *dev, struct device *master, void *data) struct vc4_dpi *dpi; int ret; - dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL); + dpi = drmm_kzalloc(drm, sizeof(*dpi), GFP_KERNEL); if (!dpi) return -ENOMEM; + dpi->encoder.type = VC4_ENCODER_TYPE_DPI; dpi->pdev = pdev; dpi->regs = vc4_ioremap_regs(pdev, 0); -- 2.11.0