On Tue, Dec 17, 2024 at 11:12 PM John Naylor <johncnaylo...@gmail.com> wrote: > > On Wed, Dec 18, 2024 at 12:49 AM Masahiko Sawada <sawada.m...@gmail.com> > wrote: > > > > Hi, > > > > I found that a server crashes due to a null-pointer-dereference if a > > process attached to the shared radix tree begins an iteration on it, > > because we don't create the memory context for iter_context at > > RT_ATTACH(). There is no code in the core causing this crash in the > > core since in parallel vacuum, the leader process always creates the > > shared radix tree and begins the iteration. However it could happen in > > external extensions. I've attached the patch to fix it and I think it > > should be backpatched to v17. > > +1 in general, but I wonder if instead the iter_context should be > created within RT_BEGIN_ITERATE -- I imagine that would have less > duplication and would be as safe, but I haven't tried it. Is there > some reason not to do that?
I agree that it has less duplication. There is no strong reason I didn't do that. I just didn't want to check 'if (!tree->iter_context)' in RT_BEGIN_ITERATE for simplicity. I've changed the patch accordingly. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
v2-0001-radixtree-Fix-crash-when-non-creator-begins-an-it.patch
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