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 zhen.ni@easystack.cn --- drivers/input/misc/uinput.c | 1 + 1 file changed, 1 insertion(+)
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; /*