On 12/3/21 14:15, Carsten Haitzler wrote:
On 12/3/21 10:09, Liviu Dudau wrote:
If drm_universal_plane_init() fails early we jump to the common cleanup code that calls komeda_plane_destroy() which in turn could access the uninitalised drm_plane and crash. Return early if an error is detected without going through the common code.
Reported-by: Steven Price steven.price@arm.com Signed-off-by: Liviu Dudau liviu.dudau@arm.com
drivers/gpu/drm/arm/display/komeda/komeda_plane.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c index aa193c58f4bf6d9..517b94c3bcaf966 100644 --- a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c +++ b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c @@ -279,8 +279,10 @@ static int komeda_plane_add(struct komeda_kms_dev *kms, komeda_put_fourcc_list(formats); - if (err) - goto cleanup; + if (err) { + kfree(kplane); + return err; + } drm_plane_helper_add(plane, &komeda_plane_helper_funcs);
Ummm... can I disagree here? this goto cleanup I think is just fine because plane has been set before drm_universal_plane_init() is called which is before the if (err) here. komeda_plane_destroy() in cleanup: does all the right things, so this patch isn't needed. I think it's less clean as it adds a new "handle error" path special-case instance where a special case is not needed. The fix to Zhou's original patch was needed for exactly the reason Liviu said - but not this one... ?
Let me take that back - it seems an init fail shouldn't call cleanup but the init fail doesn't quite cleanup properly. Steven found this and already sent a patch.