Re: [PATCH v4 0/3] hw/block/fdc: Fix CVE-2021-20196

[Kevin Wolf]

Am 24.11.2021 um 17:15 hat Philippe Mathieu-Daudé geschrieben:
> Since v3:
> - Preliminary extract blk_create_empty_drive()
> - qtest checks qtest_check_clang_sanitizer() enabled
> - qtest uses null-co:// driver instead of file
> 
> Philippe Mathieu-Daudé (3):
>   hw/block/fdc: Extract blk_create_empty_drive()
>   hw/block/fdc: Kludge missing floppy drive to fix CVE-2021-20196
>   tests/qtest/fdc-test: Add a regression test for CVE-2021-20196

If I may ask a meta question: No doubt that this is a bug and it's good
that we fixed it, but why was it assigned a CVE?

Any guest can legitimately shut down and we don't consider that a denial
of service. This bug was essentially just another undocumented way for
the guest kernel to shut down, as unprivileged users in the guest can't
normally access the I/O ports of the floppy controller. I don't think we
generally consider guests killing themselves a security problem as long
as it requires kernel or root privileges in the guest.

Kevin