Re: [HACKERS] Suspicious place in heap_prepare_freeze_tuple()

Masahiko Sawada wrote:
> On Thu, Jul 6, 2017 at 1:36 AM, Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
> > Teodor Sigaev wrote:
> >
> >> Playing around freezing tuple I found suspicious piece of code:
> >>
> >> heap_prepare_freeze_tuple():
> >> ...
> >> frz->t_infomask = tuple->t_infomask;
> >> ...
> >>             frz->t_infomask &= ~HEAP_XMAX_BITS;
> >>             frz->xmax = newxmax;
> >>             if (flags & FRM_MARK_COMMITTED)
> >>                 frz->t_infomask &= HEAP_XMAX_COMMITTED;
> >>
> >> Seems, in last line it should be a bitwise OR instead of AND. Now this line
> >> cleans all bits in t_infomask which later will be copied directly in tuple.
> >
> > I think you're right.
> 
> I also think that's right. Should we back-patch it down to 9.3?

Of course.  I think this could cause data corruption.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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