On Mon, Apr 9, 2018 at 7:11 AM, Michael Paquier <michael@paquier.xyz> wrote:
Hi all,
I was just going through pg_rewind's code, and noticed the following pearl: /* * Don't allow pg_rewind to be run as root, to avoid overwriting the * ownership of files in the data directory. We need only check for root * -- any other user won't have sufficient permissions to modify files in * the data directory. */ #ifndef WIN32 if (geteuid() == 0) { fprintf(stderr, _("cannot be executed by \"root\"\n")); fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"), progname); } #endif
While that's nice to inform the user about the problem, that actually does not prevent pg_rewind to run as root. Attached is a patch, which needs a back-patch down to 9.5.
Seems simple enough and the right hting to do, but I wonder if we should really backpatch it. Yes, the behaviour is not great now, but there is also a non-zero risk of breaking peoples automated failover scripts of we backpatch it, isn't it?
