Thread: pgsql: Catch stack overflow when recursing in transformFromClauseItem()

Catch stack overflow when recursing in transformFromClauseItem().

Most parts of the parser can expect that the stack overflow check
in transformExprRecurse() will trigger before things get desperate.
However, transformFromClauseItem() can recurse directly to self
without having analyzed any expressions, so it's possible to drive
it to a stack-overrun crash.  Add a check to prevent that.

Per bug #17583 from Egor Chindyaskin.  Back-patch to all supported
branches.

Richard Guo

Discussion: https://postgr.es/m/17583-33be55b9f981f75c@postgresql.org

Branch
------
REL_11_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/b744e13b021712d4aae3c239e8aedefc463c755f

Modified Files
--------------
src/backend/parser/parse_clause.c | 3 +++
1 file changed, 3 insertions(+)