Struct ff_effect_compat is embedded twice inside
uinput_ff_upload_compat, contains internal padding. In particular, there
is a hole after struct ff_replay to satisfy alignment requirements for
the following union member. Without clearing the structure,
copy_to_user() may leak stack data to userspace.
Initialize ff_up_compat to zero before filling valid fields.
Fixes: 2d56f3a32c ("Input: refactor evdev 32bit compat to be shareable with uinput")
Cc: stable@vger.kernel.org
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Link: https://lore.kernel.org/r/20250928063737.74590-1-zhen.ni@easystack.cn
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
d3366a0477