Re: BUG #4680: Server crashed if using wrong (mismatch) conversion functions - Mailing list pgsql-bugs

From Tom Lane
Subject Re: BUG #4680: Server crashed if using wrong (mismatch) conversion functions
Date
Msg-id 18983.1235748692@sss.pgh.pa.us
Whole thread Raw
In response to Re: BUG #4680: Server crashed if using wrong (mismatch) conversion functions  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
Responses Re: BUG #4680: Server crashed if using wrong (mismatch) conversion functions  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-bugs
Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> I think we should instead try to break the PANIC cycle. If we exceed
> ERRORDATA_STACK_SIZE, and we're already PANICing, we should just die
> immediately instead of throwing another PANIC about exceeding the stack
> size. The attached patch does that.

I don't think that's an improvement.

I'm not sure exactly why the previous fix for this type of problem
failed to cover this case --- did you identify why?

> However, a more serious issue is that a regular user can do that and
> bring down the whole system. I suggest that we make "CREATE [DEFAULT]
> CONVERSION" to call the conversion function with a empty string, to
> check that it is in fact capable of doing the conversion.

That part seems like a good idea, now that the conversion functions
throw errors (rather than Asserts) for wrong calls.

            regards, tom lane

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