Re: [REGRESSION][BISECTED] erroneous buffer overflow detected in bch2_xattr_validate

From: Thorsten Blum
Date: Thu Oct 03 2024 - 11:02:29 EST


On 3. Oct 2024, at 15:12, Jan Hendrik Farr <kernel@xxxxxxxx> wrote:
> On 03 15:07:52, Thorsten Blum wrote:
>> On 3. Oct 2024, at 13:33, Jan Hendrik Farr <kernel@xxxxxxxx> wrote:
>>>> [...]
>>>
>>> This issue is now fixed on the llvm main branch:
>>> https://github.com/llvm/llvm-project/commit/882457a2eedbe6d53161b2f78fcf769fc9a93e8a
>>
>> Thanks!
>>
>> Do you know if it also fixes the different sizes here:
>> https://godbolt.org/z/vvK9PE1Yq
>
> Unfortunately this still prints 36.

I just realized that the counted_by attribute itself causes the 4 bytes
difference. When you remove the attribute, the sizes are equal again.

>> I ran out of disk space when compiling llvm :0
>>
>>> So presumably this will go into 19.1.2, not sure what this means for
>>> distros that ship clang 18. Will they have to be notified to backport
>>> this?
>>>
>>> Best Regards
>>> Jan