[PATCH] Fix for bitcode reader crash on invalid input [PR18704]

[Reid Kleckner]

Nick and I looked at this and we think there are other issues of a similar
nature in the bitcode reader.  There are many places where ValueList is
indexed and accessed without any null check.  I think Nick said the list
shouldn't contain any null elements unless we're returning an error, which
is what your test case does.


On Sun, Mar 2, 2014 at 9:08 PM, Dinesh Dwivedi <dinesh.d at samsung.com> wrote:

> ping..
>
> Regards
> Dinesh Dwivedi
>
> ------- Original Message -------
> Sender : Dinesh Dwivedi<dinesh.d at samsung.com>  Chief
> Engineer/SRI-Bangalore-Native Framework/Samsung Electronics
> Date   : Feb 27, 2014 15:51 (GMT+05:30)
> Title  : [PATCH] Fix for bitcode reader crash on invalid input [PR18704]
>
> Hi Reid,
>
> I have attached a separate binary patch for bc file. This is same file
> attached in bug report. I have added llvm-bcanalyzer as comment in test
> case. But I do not understand much of it.
>
> I have updated my fix a bit. I have update dyn_cast to dyn_cast_or_null
> for all location casting values from ValueList to something. If code was
> already returning some error code on null value, I left them as it is. For
> other cases, I have added null check and on null it will return
> "InvalidValue".
>
> Regards
> Dinesh Dwivedi
>
>
> ------- Original Message -------
> Sender : Reid Kleckner<rnk at google.com>
> Date : Feb 27, 2014 00:16 (GMT+05:30)
> Title : Re: [PATCH] Fix for bitcode reader crash on invalid input [PR18704]
>
> The binary content of the .bc file isn't present in the diff.  Can you
> attach it, and maybe paste the output of llvm-bcanalyzer into the test case
> as a comment?  Also, the fix doesn't look correct.  It looks like
> subsequent Arguments might leak, although that isn't really critical.
>
>
>
> On Wed, Feb 26, 2014 at 7:37 AM, Dinesh Dwivedi <dinesh.d at samsung.com>
> wrote:
>
> Attaching patch for PR18704. I have just gone through back-trace for the
> assert [dyn_cast was getting applied to NULL value], locate code causing
> this and added check to print error for NULL values.
>
> Regards
> Dinesh Dwivedi
>
>
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