| Message ID | 20240407063053.5481-1-qq810974084@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V2] drm/arm/malidp: fix a possible null pointer dereference | expand |
On Sun, Apr 07, 2024 at 02:30:53PM +0800, Huai-Yuan Liu wrote: > 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> Reviewed-by: Liviu Dudau <liviu.dudau@arm.com> Thanks for the patch. I will pull it into drm-misc-fixes before the end of the week. Best regards, Liviu > --- > 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 >
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
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(-)