From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     akpm@linux-foundation.org, pmladek@suse.com,
        valentin.schneider@arm.com, peterz@infradead.org,
        keescook@chromium.org, robdclark@chromium.org,
        samitolvanen@google.com
Cc:     linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] kthread: potential dereference of null pointer
Date:   Thu,  9 Dec 2021 14:43:14 +0800
Message-Id: <20211209064314.2074885-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The return value of kzalloc() needs to be checked.
To avoid use of null pointer in case of the failure of alloc.

Fixes: dc6a87f5450d ("sched: Make the idle task quack like a per-CPU kthread")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 kernel/kthread.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index 08931e525dd9..3feefeff4922 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -101,6 +101,8 @@ void set_kthread_struct(struct task_struct *p)
 		return;
 
 	kthread = kzalloc(sizeof(*kthread), GFP_KERNEL);
+	if (!kthread)
+		return;
 	/*
 	 * We abuse ->set_child_tid to avoid the new member and because it
 	 * can't be wrongly copied by copy_process(). We also rely on fact
-- 
2.25.1