Re: Printing backtrace of postgres processes

On Mon, Feb 1, 2021 at 6:14 AM Bharath Rupireddy
<bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote:
> On Fri, Jan 29, 2021 at 7:10 PM vignesh C <vignesh21(at)gmail(dot)com> wrote:
> > > 4) How about following
> > > + errmsg("must be a superuser to print backtrace
> > > of backend process")));
> > > instead of
> > > + errmsg("must be a superuser to print backtrace
> > > of superuser query process")));
> > >
> >
> > Here the message should include superuser, we cannot remove it. Non
> > super user can log non super user provided if user has permissions for
> > it.
> >
> > > 5) How about following
> > > errmsg("must be a member of the role whose backed
> > > process's backtrace is being printed or member of
> > > pg_signal_backend")));
> > > instead of
> > > + errmsg("must be a member of the role whose
> > > backtrace is being logged or member of pg_signal_backend")));
> > >
> >
> > Modified it.
>
> Maybe I'm confused here to understand the difference between
> SIGNAL_BACKEND_NOSUPERUSER and SIGNAL_BACKEND_NOPERMISSION macros and
> corresponding error messages. Some clarification/use case to know in
> which scenarios we hit those error messages might help me. Did we try
> to add test cases that show up these error messages for
> pg_print_backtrace? If not, can we add?

Are these superuser and permission checks enough from a security
standpoint that we don't expose some sensitive information to the
user? Although I'm not sure, say from the backtrace printed and
attached to GDB, can users see the passwords or other sensitive
information from the system that they aren't supposed to see?

I'm sure this point would have been discussed upthread.

With Regards,
Bharath Rupireddy.
EnterpriseDB: http://www.enterprisedb.com