Re: pg_control is missing a field for LOBLKSIZE

Stephen Frost <sfrost(at)snowman(dot)net> writes:
> * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
>> There are at least two places in inv_api.c where we have
>> "Assert(pagelen <= LOBLKSIZE)" that is protecting a subsequent memcpy
>> into a local variable of size LOBLKSIZE, so that the only thing standing
>> between us and a stack-smash security issue that's trivially exploitable
>> in production builds is that on-disk data conforms to our expectation
>> about LOBLKSIZE. I think it's definitely worth promoting these checks
>> to regular runtime-if-test-and-elog.

> Agreed. Promoting that to a run-time check seems well worth it to me.

Here's a draft patch for this. Barring objections I'll commit the whole
thing to HEAD, and the inv_api.c changes to the back branches as well.

regards, tom lane