[CHECKER] 9 potential out-of-bounds array access errors

["Yichen Xie" <yxie(at)cs(dot)stanford(dot)edu>]

Hi all,

We are a group of Stanford researchers, and we've recently developed a
tool that detects potential out-of-bounds array accesses and buffer
overruns. Here are 9 potential bugs we've found on postgresql 7.3.1.
We've been checking linux for a few years, and we're interested in
expanding to other system software as well. Let us know if you guys are
interested in bug reports like this. Confirmation and comments will be
appreciated.

Regards,
Yichen
Meta Compilation Group
http://metacomp.stanford.edu (little out of date tho)

############################################################
# New errors.
#
---------------------------------------------------------
[BUG] MAX_TIME_PRECISION defined to be 13 when HAVE_INT64_TIMESTAMP is
not defined
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/adt/date.c:682:AdjustTimeFor
Typmod: ERROR:BUFFER:682:682:Array bounds error (off >= len) [RANGE]
(TimeScales[typmod], len = 7, off = sym_905407, max(off-len) = 6) 

		}
#else
		/* we have different truncation behavior depending on
sign */
		if (*time >= 0)
		{

Error --->
			*time = (rint(((double) *time) *
TimeScales[typmod])
					 / TimeScales[typmod]);
		}
		else
---------------------------------------------------------
[BUG] "i" can go up to 13
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/mb/conversion_procs/euc_tw_a
nd_big5/big5.c:364:CNStoBIG5: ERROR:BUFFER:364:364:Array bounds error
(off >= len) (b2c3[i], len = 7, off = 7, min(off-len) = 0) 

			big5 = BinarySearchRange(cnsPlane2ToBig5Level2,
47, cns);
			break;
		case LC_CNS11643_3:
			for (i = 0; i < sizeof(b2c3) / sizeof(unsigned
short); i++)
			{

Error --->
				if (b2c3[i][1] == cns)
					return (b2c3[i][0]);
			}
			break;
---------------------------------------------------------
[BUG] "i" can go up to 13
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/mb/conversion_procs/euc_tw_a
nd_big5/big5.c:371:CNStoBIG5: ERROR:BUFFER:371:371:Array bounds error
(off >= len) (b1c4[i], len = 4, off = 4, min(off-len) = 0) 

			}
			break;
		case LC_CNS11643_4:
			for (i = 0; i < sizeof(b1c4) / sizeof(unsigned
short); i++)
			{

Error --->
				if (b1c4[i][1] == cns)
					return (b1c4[i][0]);
			}
		default:
---------------------------------------------------------
[BUG] is plpgsql_nDatums 0 here? also, sizeof (plpgsql_nDatums) =
2*sizeof(PLpgSQL_datum *)
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/pl/plpgsql/src/pl_comp.c:527:plpgsql_compi
le: ERROR:BUFFER:527:527:Dereferencing uninitialized pointer
(*(*function).datums + (PLpgSQL_datum**)(Oid)i * 4) evaluated in the
following state 

	for (i = 0; i < function->fn_nargs; i++)
		function->fn_argvarnos[i] = arg_varnos[i];
	function->ndatums = plpgsql_nDatums;
	function->datums = malloc(sizeof(PLpgSQL_datum *) *
plpgsql_nDatums);
	for (i = 0; i < plpgsql_nDatums; i++)

Error --->
		function->datums[i] = plpgsql_Datums[i];
	function->action = plpgsql_yylval.program;

	ReleaseSysCache(procTup);
---------------------------------------------------------
[BUG] does fe_setauthsvc abort the function? if not there's a
possibility of an overrun
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/interfaces/libpq/fe-auth.c:688:fe_getauths
vc: ERROR:BUFFER:688:688:Array bounds error (off >= len)
(authsvcs[pg_authsvc], len = 2, off = sym_3532626, min(off-len) = 0) 

MsgType
fe_getauthsvc(char *PQerrormsg)
{
	if (pg_authsvc < 0 || pg_authsvc >= n_authsvcs)
		fe_setauthsvc(DEFAULT_CLIENT_AUTHSVC, PQerrormsg);

Error --->
	return authsvcs[pg_authsvc].msgtype;
}

/*
---------------------------------------------------------
[BUG] "i" can go up to 13
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/mb/conversion_procs/euc_tw_a
nd_big5/big5.c:325:BIG5toCNS: ERROR:BUFFER:325:325:Array bounds error
(off >= len) (b2c3[i], len = 7, off = 7, min(off-len) = 0) 

	else
	{
		/* level 2 */
		for (i = 0; i < sizeof(b2c3) / sizeof(unsigned short);
i++)
		{

Error --->
			if (b2c3[i][0] == big5)
			{
				*lc = LC_CNS11643_3;
				return (b2c3[i][1] | 0x8080U);
---------------------------------------------------------
[BUG] MAX_TIME_PRECISION is 13
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/adt/date.c:691:AdjustTimeFor
Typmod: ERROR:BUFFER:691:691:Array bounds error (off >= len) [RANGE]
(TimeOffsets[typmod], len = 7, off = sym_905407, max(off-len) = 6) 

		{
			/*
			 * Scale and truncate first, then add to help
the rounding
			 * behavior
			 */

Error --->
			*time = (rint((((double) *time) *
TimeScales[typmod]) + TimeOffsets[typmod])
					 / TimeScales[typmod]);
		}
#endif
---------------------------------------------------------
[BUG]
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/mb/conversion_procs/euc_tw_a
nd_big5/big5.c:304:BIG5toCNS: ERROR:BUFFER:304:304:Array bounds error
(off >= len) (b1c4[i], len = 4, off = 4, min(off-len) = 0) 

	{
		/* level 1 */

		for (i = 0; i < sizeof(b1c4) / sizeof(unsigned short);
i++)
		{

Error --->
			if (b1c4[i][0] == big5)
			{
				*lc = LC_CNS11643_4;
				return (b1c4[i][1] | 0x8080U);
---------------------------------------------------------
[BUG] ndim can be 0...
X [FALSE]
X [UNKNOWN]
X [BROKE]
X [SKIP]
/u2/yxie/postgresql-7.3.1/src/backend/utils/adt/arrayfuncs.c:352:ArrayCo
unt: ERROR:BUFFER:352:352:Array bounds error (off < 0) (temp[ndim - 1],
max(off) = -1) 

					break;
			}
			if (!itemdone)
				ptr++;
		}

Error --->
		temp[ndim - 1]++;
		ptr++;
	}
	for (i = 0; i < ndim; ++i)


############################################################
# Existing, unfixed errors
#


############################################################
# Existing, skipped errors
#


############################################################
# Existing unknown 
#


############################################################
# Existing false positives 
#


############################################################


############################################################
# New Fixed errors
#


############################################################
# Old fixed
#


############################################################

# Summary for BUFFER
#    New errors              = 9
#    Existing unfixed errors = 0
#    Existing unfixed skip   = 0
#    Existing unknown 	     = 0
#    Existing false pos      = 0
#    Mismatch errors         = 0
#    Fixed errors            = 0
#    Fixed false/broke       = 0
#    Fixed unknown           = 0
#    Old fixed               = 0