Re: [PATCH v2 13/19] udf: prevent bounds-check bypass via speculative execution

From: Dan Williams
Date: Mon Jan 15 2018 - 12:49:29 EST


On Mon, Jan 15, 2018 at 2:32 AM, Jan Kara <jack@xxxxxxx> wrote:
> On Thu 11-01-18 16:47:35, Dan Williams wrote:
>> Static analysis reports that 'eahd->appAttrLocation' and
>> 'eahd->impAttrLocation' may be a user controlled values that are used as
>> data dependencies for calculating source and destination buffers for
>> memmove operations. In order to avoid potential leaks of kernel memory
>> values, block speculative execution of the instruction stream that could
>> issue further reads based on invalid 'aal' or 'ial' values.
>>
>> Based on an original patch by Elena Reshetova.
>>
>> Cc: Jan Kara <jack@xxxxxxxx>
>> Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
>> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
>
> Dan, I've already emailed to you [1] why I don't think this patch is needed
> at all. Do you disagree or did my email just get lost?
>
> [1] https://marc.info/?l=linux-arch&m=151540683024125&w=2

Sorry, I missed that one before the v2 posting went out. I've dropped
this from the v3 [1] posting.

[1]: https://marc.info/?l=linux-kernel&m=151586794400997&w=2