Re: MemoryContextAlloc: invalid request size 1934906735

On August 27, 2002 02:01 am, Tom Lane wrote:
> "D'Arcy J.M. Cain" <darcy(at)druid(dot)net> writes:
> > I have been getting the subject message ever since upgrading to 7.2.1. I
> > tried 7.2.2 with the same thing. It seems to be related to my chkpass
> > type (see contrib) as it only happens on tables with that type.
>
> FWIW, I couldn't see any problem in CVS tip. Could you provide an exact
> sequence-to-reproduce?

Surely. Create a database (chkpass_test) and, after loading the chkpass
type, follow this bouncing ball.

1. CREATE TABLE x (c chkpass);
2. INSERT INTO x VALUES ('a'); [Repeat 20 times]
3. VACUUM ANALYZE x;
4. UPDATE x SET c = ':a';
5. VACUUM ANALYZE x;
6. UPDATE x SET c = 'a';
7. VACUUM ANALYZE x;
8. GOTO 4

Note that 3 and 7 should fail most (95%?) of the time. When it does, convert
the invalid size to hex and compare the bytes of the integer with the
encrypted value in the table.

Note that the fact that 5 does not fail has nothing to do with the path
through chkpass.c. If you take a failing password and insert it raw with
"UPDATE x SET c = ':2w3dhratDt7xo';" then you get the same failure (even the
same number - 1952543340 in my case) as you did when chkpass encrypted with
that salt.

--
D'Arcy J.M. Cain <darcy(at){druid|vex}.net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
+1 416 425 1212 (DoD#0082) (eNTP) | what's for dinner.