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Subject: Re: [PATCH][next] io-wq: fix unintentional integer overflow on left
 shift
To:     Colin Ian King <colin.king@canonical.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel@vger.kernel.org
Cc:     kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20191025124315.21742-1-colin.king@canonical.com>
 <fc23061e-31ec-8a66-2b62-771121d182de@kernel.dk>
 <02517010-9244-771f-d0ce-558bbebe6a63@kernel.dk>
 <a13505ab-52f1-b47d-7b1d-45552982fc82@canonical.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <4a750188-2696-c35a-9c5a-8bfe509edf14@kernel.dk>
Date:   Fri, 25 Oct 2019 07:59:38 -0600
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On 10/25/19 7:59 AM, Colin Ian King wrote:
> On 25/10/2019 14:56, Jens Axboe wrote:
>> On 10/25/19 6:54 AM, Jens Axboe wrote:
>>> On 10/25/19 6:43 AM, Colin King wrote:
>>>> From: Colin Ian King <colin.king@canonical.com>
>>>>
>>>> Shifting the integer value 1U is evaluated with type unsigned int
>>>> using 32-bit arithmetic and then used in an expression that expects
>>>> a 64-bit value, so there is potentially an integer overflow. Fix this
>>>> by using the BIT_ULL macro to perform the shift and avoid the overflow.
>>>
>>> Good catch, that should indeed have been 1ULL. I'll fold in your
>>> fix, thanks!
>>
>> BTW, this missed the same issue on the clear side of it, in
>> io_worker_handle_work(). I've fixed that one up the same way.
>>
> Ah, good, somehow the scanner missed that.

Something to take a look at! :-)

-- 
Jens Axboe