dc(1) fails with "big number failure" on 2^64

[Jan Mikkelsen]

Hi,

I am seeing this in dc:

janm at gray: dc $ dc
18446744073709551616 18446744073709551616 / ps
dc: big number failure 306b06b: No such file or directory

That number is 2^64. The error is coming from BN_check in bdiv(), which is complaining about the number at the top of the stack being uninitialised. Looking at the data, after the second pop in bdiv() in bdata.c, b->number->d[b->number->top - 1] == 0. After a while poking around in a debugger, it looks like the first word of the second number (a->number->d) is being allocated at the same location as the last word of the second number, it gets zeroed, and then looks uninitialised.

All of this seems to be happening in the BN_* routines in openssl.

I am seeing this on my builds for 9.1-RC3 and 9.0-p3, as well as the CDROM shell on the 9.1-RC3 ISO, so I'm pretty sure it isn't my build process or compiler flags. I have checked an OpenBSD 5.2 installation, and it works fine.

Can anyone confirm this? Am I just seeing things? Is there an obvious fix?

Thanks,

Jan Mikkelsen