Messages in this thread Patch in this message | | | From | Huai-Yuan Liu <> | Subject | [PATCH V2] drm/arm/malidp: fix a possible null pointer dereference | Date | Sun, 7 Apr 2024 14:30:53 +0800 |
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In malidp_mw_connector_reset, new memory is allocated with kzalloc, but no check is performed. In order to prevent null pointer dereferencing, ensure that mw_state is checked before calling __drm_atomic_helper_connector_reset.
Fixes: 8cbc5caf36ef ("drm: mali-dp: Add writeback connector") Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com> --- V2: * In patch V2, we additionally set connector->state to NULL. In this way we can ensure that there is no state pointing to freed memory. Thanks to Liviu Dudau for helpful suggestion. --- drivers/gpu/drm/arm/malidp_mw.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c index 626709bec6f5..2577f0cef8fc 100644 --- a/drivers/gpu/drm/arm/malidp_mw.c +++ b/drivers/gpu/drm/arm/malidp_mw.c @@ -72,7 +72,10 @@ static void malidp_mw_connector_reset(struct drm_connector *connector) __drm_atomic_helper_connector_destroy_state(connector->state); kfree(connector->state); - __drm_atomic_helper_connector_reset(connector, &mw_state->base); + connector->state = NULL; + + if (mw_state) + __drm_atomic_helper_connector_reset(connector, &mw_state->base); } static enum drm_connector_status -- 2.34.1
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