[PATCH] signal: check sig before setting info in kill_pid_usb_asyncio

From: Zhiqiang Liu <liuzhiqiang26@huawei.com>
To: <ebiederm@xmission.com>, <christian.brauner@ubuntu.com>,
	<oleg@redhat.com>, <tj@kernel.org>, <guro@fb.com>,
	<joel@joelfernandes.org>, <jannh@google.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: Mingfangsen <mingfangsen@huawei.com>,
	Yanxiaodan <yanxiaodan@huawei.com>,
	linfeilong <linfeilong@huawei.com>
Subject: [PATCH] signal: check sig before setting info in kill_pid_usb_asyncio
Date: Mon, 30 Mar 2020 10:18:33 +0800	[thread overview]
Message-ID: <f525fd08-1cf7-fb09-d20c-4359145eb940@huawei.com> (raw)


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

Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
---
 kernel/signal.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 9ad8dea93dbb..9cdc9e388a19 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1505,15 +1505,15 @@ 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) {
-- 
2.19.1

