[PATCH 6.1 221/473] drm/arm/malidp: fix a possible null pointer dereference

Greg Kroah-Hartman
2024-06-06T14:15:39Z

From: Huai-Yuan Liu <qq810974084@gmail.com>

[ Upstream commit a1f95aede6285dba6dd036d907196f35ae3a11ea ]

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>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240407063053.5481-1-qq810974084@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 ef76d0e6ee2fc..389d32994135b 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
--
2.43.0