signal: check sig before setting info in kill_pid_usb_asyncio

In kill_pid_usb_asyncio, if signal is not valid, we do not need to
set info struct.

Signed-off-by: Zhiqiang Liu <[email protected]>
Acked-by: Christian Brauner <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: ZhiqiangLiu26

kernel/signal.c

@@ -1510,15 +1510,15 @@ int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr,
 	unsigned long flags;
 	int ret = -EINVAL;
 
+	if (!valid_signal(sig))
+		return ret;
+
 	clear_siginfo(&info);
 	info.si_signo = sig;
 	info.si_errno = errno;
 	info.si_code = SI_ASYNCIO;
 	*((sigval_t *)&info.si_pid) = addr;
 
-	if (!valid_signal(sig))
-		return ret;
-
 	rcu_read_lock();
 	p = pid_task(pid, PIDTYPE_PID);
 	if (!p) {