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

[Thorsten Blum]

On 28. Sep 2024, at 22:34, Kees Cook <kees@xxxxxxxxxx> wrote:
> [...]
> 
> Sorry, I've been out of commission with covid. Globally disabling this
> macro for clang is not the right solution (way too big a hammer).
> 
> Until Bill has a fix, we can revert commit
> 86e92eeeb23741a072fe7532db663250ff2e726a, as the problem is limited to
> certain situations where 'counted_by' is in use.

I already encountered two other related __counted_by() issues [1][2]
that are now being reverted. Would it be an option to disable it
globally, but only for Clang < v19 (where it looks like it'll be fixed)?

Otherwise adding __counted_by() might be a slippery slope for a long
time and the edge cases don't seem to be that rare anymore.

Thanks,
Thorsten

[1] https://lore.kernel.org/all/20240909162725.1805-2-thorsten.blum@xxxxxxxxxx/
[2] https://lore.kernel.org/all/20240923213809.235128-2-thorsten.blum@xxxxxxxxx/