From c0c70a11365cba7fba25a77463582bcec0f7846e Mon Sep 17 00:00:00 2001 From: Dmitry Baryshkov Date: Tue, 5 May 2026 03:24:58 +0300 Subject: [PATCH] drm/msm/dpu: don't mix devm and drmm functions Mixing devm and drmm functions will result in a use-after-free on msm driver teardown if userspace keeps a reference on the drm device: The WB connector data will be destroyed because of the use of devm_kzalloc()), while the usersoace still can try interacting with the WB connector (which uses drmm_ functions). Change dpu_writeback_init() to use drmm_. Fixes: 0b37ac63fc9d ("drm/msm/dpu: use drmm_writeback_connector_init()") Reported-by: Christophe JAILLET Closes: https://lore.kernel.org/r/78c764b8-44cf-4db5-88e7-807a85954518@wanadoo.fr Signed-off-by: Dmitry Baryshkov Reviewed-by: John.Harrison@Igalia.com Patchwork: https://patchwork.freedesktop.org/patch/722656/ Link: https://lore.kernel.org/r/20260505-wb-drop-encoder-v5-1-42567b7c7af2@oss.qualcomm.com --- drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c index 7545c0293efb..6f2370c9dd98 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c @@ -5,6 +5,7 @@ #include #include +#include #include "dpu_writeback.h" @@ -125,7 +126,7 @@ int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc, struct dpu_wb_connector *dpu_wb_conn; int rc = 0; - dpu_wb_conn = devm_kzalloc(dev->dev, sizeof(*dpu_wb_conn), GFP_KERNEL); + dpu_wb_conn = drmm_kzalloc(dev, sizeof(*dpu_wb_conn), GFP_KERNEL); if (!dpu_wb_conn) return -ENOMEM;