CodeSonar : Pvm : Use After Free

Pvm : Pvm analysis 1 : Use After Free at cmds.c:499

Categories:	LANG.ALLOC.UAF CWE:416
Warning ID:	2916.2998
Procedure:	newalias
Trace:	View
Modified:	Wed Sep 2 12:52:43 2009 show details hide details

Priority:	None
State:	None
Finding:	None
Owner:	None
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Warning Location Contributes Parse Error Other Warning Two or More Loop Iterations On Execution Path Comment Macro Preprocessor Include Keyword Preprocessed Away

Legend
Warning Location	Contributes	Parse Error
Other Warning	Two or More Loop Iterations	On Execution Path
Comment	Macro	Preprocessor
Include	Keyword	Preprocessed Away

Source | Language: C

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Problem	Line	Source

			/u1/paul/SATE/2010/c/pvm/pvm3/console/cmds.c

			Enter alias_cmd

	1385		alias_cmd(ac, av)
	1386		int ac;
	1387		char **av;
	1388		{
	1389		struct alias *ap;
	1390		char *p;
	1391		int i;
	1392
	1393		if (ac < 3) {
	1394		for (ap = aliases->a_link; ap != aliases; ap = ap->a_link) {
	1395		fputs(ap->a_name, stdout);
	1396		p = "\t";
	1397		for (i = 0; i < ap->a_num; i++) {
	1398		printf("%s%s", p, ap->a_args[i]);
	1399		p = " ";
	1400		}
	1401		fputs("\n", stdout);
	1402		}
	1403
	1404		} else {

true

1405

if (ap = findalias (av[1]))

	1406		freealias(ap );

*aliases->a_link is freed

1407

newalias (av[1], ac - 2, av + 2);

					Enter alias_cmd / newalias

484

struct alias *

485

newalias(name, num, args)

char *name;

int num;

char **args;

{

struct alias *ap, *ap2;

491

492

ap = TALLOC(1, struct alias, "alias");

493

ap->a_name = STRALLOC(name); /* Null Pointer Dereference (ID: 2912.2985) */

494

ap->a_args = TALLOC(num + 1, char *, "aargs");

495

ap->a_num = num;

496

while (num-- > 0)

497

ap->a_args[num] = STRALLOC(args[num]); /* Null Pointer Dereference (ID: 2911.2983) */

*aliases->a_link is freed

498

for (ap2 = aliases->a_link; ap2 != aliases; ap2 = ap2->a_link)

*ap2 is freed

499

if (strcmp(ap2->a_name, name) > 0) /* Use After Free */

					Exit alias_cmd / newalias

Preconditions

$param_1 >= 3
aliases->a_link->a_num >= 1
strlen(aliases->a_link->a_name) = strlen(((char*)$param_2)[8])
aliases->a_link != aliases

Postconditions

aliases->a_link->a_link->a_rlink' = aliases->a_link->a_rlink
aliases->a_link->a_num' = -1
aliases->a_link->a_rlink' = 0
*aliases->a_link->a_name' is freed
*aliases->a_link->a_args' is freed
aliases->a_link->a_rlink->a_link' = aliases->a_link->a_link
aliases->a_link->a_link' = 0
*aliases->a_link' is freed
ac' = $param_1
ap' = aliases->a_link
ap' = &$heap_240182
ap2' = aliases->a_link
args' = $param_2 + 16
av' = $param_2
bytes_after(&$heap_240182)' = 48
$heap_240182' is allocated by malloc
$heap_240182' is allocated
bytes_before(&$heap_240182)' = 0
((char*)&$heap_240182)[16]' = &$heap_240183
((char*)&$heap_240182)[24]' = $param_1 - 2
((char*)&$heap_240182)[32]' = &$heap_240184
$heap_240183' = ((char*)*$param_2)[8]
bytes_after(&$heap_240183)' = strlen(((char*)$param_2)[8]) + 1
$heap_240183' is allocated by malloc
$heap_240183' is allocated
bytes_before(&$heap_240183)' = 0
strlen(&$heap_240183)' = strlen(((char*)$param_2)[8])
bytes_after(&$heap_240184)' = 8 * $param_1 - 8
$heap_240184' is allocated by malloc
$heap_240184' is allocated
bytes_before(&$heap_240184)' = 0
name' = ((char*)$param_2)[8]
num' = -1

Change Warning 2916.2998 : Use After Free

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