2022-01-14 09:45:06

by Jiasheng Jiang

Subject: [PATCH] drm/arm/mali: Check for NULL pointer after calling kzalloc

As the possible failure of the kzalloc(), mw_state could be NULL
pointer.
Therefore, it should be better to check it in order to avoid the
dereference of the NULL pointer, like the kzalloc() in
malidp_mw_connector_duplicate_state().
If fails, we can directly use the 'NULL' instead of the
'&mw_state->base' and __drm_atomic_helper_connector_reset() will deal
with it correctly.

Fixes: 8cbc5caf36ef ("drm: mali-dp: Add writeback connector")
Signed-off-by: Jiasheng Jiang <[email protected]>
---
drivers/gpu/drm/arm/malidp_mw.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_mw.c b/drivers/gpu/drm/arm/malidp_mw.c
index f5847a79dd7e..96752353b5a1 100644
--- a/drivers/gpu/drm/arm/malidp_mw.c
+++ b/drivers/gpu/drm/arm/malidp_mw.c
@@ -70,7 +70,11 @@ 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);
+
+ if (!mw_state)
+ __drm_atomic_helper_connector_reset(connector, NULL);
+ else
+ __drm_atomic_helper_connector_reset(connector, &mw_state->base);
}

static enum drm_connector_status
--
2.25.1

2022-01-14 09:55:17

by Jiasheng Jiang

Subject: Re: [PATCH] drm/arm/mali: Check for NULL pointer after calling kzalloc

Sorry, I just noticed that I have already sent the patch before and it has been reviewed.
Please ignore this one.

Sincerely thanks,
Jiang