From: Maxime Ripard Date: Mon, 11 Jul 2022 17:38:55 +0000 (+0200) Subject: drm/vc4: dpi: Switch to drmm_kzalloc X-Git-Tag: v6.1-rc5~176^2~22^2~214 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7f0ba8f98a4ec3bee6a5d612e676a75791c0f127;p=platform%2Fkernel%2Flinux-starfive.git 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 --- diff --git a/drivers/gpu/drm/vc4/vc4_dpi.c b/drivers/gpu/drm/vc4/vc4_dpi.c index 7c4bfbd..7a1112c 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);