Re: [PATCH][V2] RDMA/nes: do not leak uninitialized resp.reserved to userspace Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit

From: Colin Ian King
Date: Tue Sep 05 2017 - 10:45:18 EST


On 05/09/17 15:40, Chien Tin Tung wrote:
> On Mon, Sep 04, 2017 at 02:37:05PM +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>
>> resp.reserved has not been initialized and so the copy_to_user (via
>> ib_copy_to_udata) is copying uninitialized data from the stack back
>> to user space which is a potential information leak. Fix this by
>> initializing all of resp to zero.
>
> Reserved field is not copied as the length of reserved is subtracted
> from the size of resp and passed to ib_copy_to_udata.
>
> if (ib_copy_to_udata(udata, &resp, sizeof resp - sizeof resp.reserved)) {
>
>
> This patch is not necessary.

Apologies, I completely overlooked that.

>
> Chien
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