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Date: Mon, 5 Jun 2017 21:46:02 +0800
From: zhong jiang <zhongjiang@huawei.com>
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To: Oleg Nesterov <oleg@redhat.com>
CC: <akpm@linux-foundation.org>, <mhocko@kernel.org>, <vbabka@suse.cz>,
        <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <qiuxishi@huawei.com>
Subject: Re: [PATCH v2] signal: Avoid undefined behaviour in kill_something_info
References: <1496667207-56723-1-git-send-email-zhongjiang@huawei.com> <20170605133159.GA10301@redhat.com>
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On 2017/6/5 21:31, Oleg Nesterov wrote:
> On 06/05, zhongjiang wrote:
>> --- a/kernel/signal.c
>> +++ b/kernel/signal.c
>> @@ -1395,6 +1395,12 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
>>
>>  	read_lock(&tasklist_lock);
>>  	if (pid != -1) {
>> +		/*
>> +	 	 * -INT_MIN is undefined, it need to exclude following case to
>> + 		 * avoid the UBSAN detection.
>> +		 */
>> +		if (pid == INT_MIN)
>> +			return -ESRCH;
> you need to do this before read_lock(tasklist)
>
> Oleg.
>
>
> .
>
  I am so sorry for disturbing.

 Thanks
zhongjiang