Re: write past chunk end in ExprContext / to_char

[imad <immaad(at)gmail(dot)com>]

This is the problematic part in formatting.c, function "dch_time".

				int			siz = strlen(tmtcTzn(tmtc));

				if (arg == DCH_TZ)
					strcpy(inout, tmtcTzn(tmtc));
				else
				{
					char	   *p = palloc(siz);

					strcpy(p, tmtcTzn(tmtc));
					strcpy(inout, str_tolower(p));
					pfree(p);
				}
				return siz;


here, doing a palloc with "siz+1" solves the issue but following /
making the convention, pstrdup should be used instead which is
specifically written for this purpose.

Probably too small a change for a patch ?


--Imad
www.EnterpriseDB.com


On 6/29/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Patrick Welche <prlw1(at)newn(dot)cam(dot)ac(dot)uk> writes:
> > With today's CVS code (originally noticed with 8.2beta3), on a PC where
> > INT_MAX=0x7FFFFFFF=2147483647
>
> > postgres=# select to_char(2147483648,'999,999,999');
> > WARNING:  detected write past chunk end in ExprContext 0x845509c
> > WARNING:  detected write past chunk end in ExprContext 0x845509c
>
> Yech ... it's scribbling on the output of int8out, which is bad enough,
> but it's assuming that buffer will be long enough when it demonstrably
> isn't.
>
> Some days I think we ought to throw out formatting.c and rewrite it from
> scratch; it's probably the most poorly-coded module in all of Postgres.
>
>                         regards, tom lane
>
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