From: Zhen Ni Date: Sun, 28 Sep 2025 06:37:37 +0000 (+0800) Subject: Input: uinput - zero-initialize uinput_ff_upload_compat to avoid info leak X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d3366a04770eea807f2826cbdb96934dd8c9bf79;p=users%2Fhch%2Fmisc.git Input: uinput - zero-initialize uinput_ff_upload_compat to avoid info leak 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: 2d56f3a32c0e ("Input: refactor evdev 32bit compat to be shareable with uinput") Cc: stable@vger.kernel.org Signed-off-by: Zhen Ni Link: https://lore.kernel.org/r/20250928063737.74590-1-zhen.ni@easystack.cn Signed-off-by: Dmitry Torokhov --- diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 2c51ea9d01d7..13336a2fd49c 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -775,6 +775,7 @@ static int uinput_ff_upload_to_user(char __user *buffer, if (in_compat_syscall()) { struct uinput_ff_upload_compat ff_up_compat; + memset(&ff_up_compat, 0, sizeof(ff_up_compat)); ff_up_compat.request_id = ff_up->request_id; ff_up_compat.retval = ff_up->retval; /*