Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 4.14 17/89] futex: Prevent overflow by strengthen input
 validation
To:     Thomas Gleixner <tglx@linutronix.de>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Li Jinyue <lijinyue@huawei.com>, peterz@infradead.org,
        dvhart@infradead.org
References: <20180122083954.683903493@linuxfoundation.org>
 <20180122083956.427607580@linuxfoundation.org>
 <20567b49-e0a3-e9e0-d520-74bbfc20d414@suse.cz>
 <alpine.DEB.2.20.1801251502310.2020@nanos>
From:   Jiri Slaby <jslaby@suse.cz>
Message-ID: <ab877235-a584-1769-a322-f3451bee5ec6@suse.cz>
Date:   Thu, 25 Jan 2018 15:06:12 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.5.2
MIME-Version: 1.0
In-Reply-To: <alpine.DEB.2.20.1801251502310.2020@nanos>
Content-Type: text/plain; charset=iso-8859-2
Content-Language: en-GB
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 01/25/2018, 03:03 PM, Thomas Gleixner wrote:
> On Thu, 25 Jan 2018, Jiri Slaby wrote:
>> On 01/22/2018, 09:44 AM, Greg Kroah-Hartman wrote:
>>> +	if (nr_wake < 0 || nr_requeue < 0)
>>> +		return -EINVAL;
>>
>> This breaks strace's test suite on 4.14.15 (and is present in upstream
>> obviously too):
>>     futex(0x7ff568b44ffc, 0x3, 0xfacefeed, 0xbadda7a0ca7b100d,
>> 0x7ff568b44ffc, 0x9caffee1) = -1: Invalid argument
> 
> And why the hell is strace expecting this to be valid?

You ought to ask somebody else, I was confused the very same way:

My FIX:
https://github.com/strace/strace/pull/16/commits/777587ea509481666274df88671949b390f05cc3

Their NACK:
https://github.com/strace/strace/pull/16#issuecomment-341614984

thanks,
-- 
js
suse labs