On 2023-06-28 03:32, Gisle Vanem wrote:
> 'PTRDIFF_T_MAX - - 3' folds to '-9223372036854775806'.
> 
> But how can 'linbuf_base' become negative?

Ordinarily it's zero, but it can be negative. It's never positive.

Thanks for the report. I reproduced the signed integer overflow issue 
with -fsanitize=undefined and installed the attached patch to fix it and 
add a regression test (and also a comment about linbuf_base).

Although I don't see how this would fix a "memory exhausted" error, 
please give the latest Git commit a try and see whether it fixes things 
for you.