From 98cad4bd1443975d972f4c7f705980da03722a22 Mon Sep 17 00:00:00 2001 From: Evgenii Burenchev Date: Mon, 29 Jun 2026 15:58:50 -0500 Subject: [PATCH] drm/amd/display: Fix dangling pointer in plane reset function amdgpu_dm_plane_drm_plane_reset() frees the old state before allocating a new one. If kzalloc() fails, the function returns without updating the state pointer, leaving a dangling pointer to already freed memory. Fix this by allocating the new state first. On allocation failure, the old state remains untouched and the function safely returns. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 5d945cbcd4b1 ("drm/amd/display: Create a file dedicated to planes") Signed-off-by: Evgenii Burenchev Reviewed-by: Mario Limonciello (AMD) Link: https://patch.msgid.link/20260629090435.9729-3-evg28bur@yandex.ru [adjust for movement around current amd-staging-drm-next] Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c index 35813a39ebcb..1b564cfe2120 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c @@ -1517,17 +1517,15 @@ static const struct drm_plane_helper_funcs dm_primary_plane_helper_funcs = { static void amdgpu_dm_plane_drm_plane_reset(struct drm_plane *plane) { - struct dm_plane_state *amdgpu_state = NULL; + struct dm_plane_state *amdgpu_state; + + amdgpu_state = kzalloc_obj(*amdgpu_state); + if (!amdgpu_state) + return; if (plane->state) plane->funcs->atomic_destroy_state(plane, plane->state); - amdgpu_state = kzalloc_obj(*amdgpu_state); - WARN_ON(amdgpu_state == NULL); - - if (!amdgpu_state) - return; - __drm_atomic_helper_plane_reset(plane, &amdgpu_state->base); amdgpu_state->degamma_tf = AMDGPU_TRANSFER_FUNCTION_DEFAULT; amdgpu_state->hdr_mult = AMDGPU_HDR_MULT_DEFAULT;