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From: Hillf Danton <hdanton@sina.com>
To: syzbot <syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com>
Cc: linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [net?] [virt?] [kvm?] KASAN: slab-use-after-free Read in vhost_task_fn
Date: Tue, 30 Apr 2024 19:02:09 +0800
Message-Id: <20240430110209.4310-1-hdanton@sina.com>
In-Reply-To: <000000000000a9613006174c1c4c@google.com>
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On Tue, 30 Apr 2024 01:25:26 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    bb7a2467e6be Add linux-next specific files for 20240426
> git tree:       linux-next
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16c30028980000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git  bb7a2467e6be

--- x/kernel/vhost_task.c
+++ y/kernel/vhost_task.c
@@ -100,6 +100,8 @@ void vhost_task_stop(struct vhost_task *
 	 * freeing it below.
 	 */
 	wait_for_completion(&vtsk->exited);
+	mutex_lock(&vtsk->exit_mutex);
+	mutex_unlock(&vtsk->exit_mutex);
 	kfree(vtsk);
 }
 EXPORT_SYMBOL_GPL(vhost_task_stop);
--