cutils: Assert in-range base for string-to-integer conversions

POSIX states that the value of endptr is unspecified if strtol()
fails with EINVAL due to an invalid base argument.  Since none of
the callers to check_strtox_error() initialized endptr, we could
end up propagating uninitialized data back to a caller on error.
However, passing an out-of-range base is already a sign of poor
programming, so let's just assert that base is in range, at which
point check_strtox_error() can be tightened to assert that it is
receiving an initialized ep that points somewhere within the
caller's original string, regardless of whether strto*() succeeded
or failed with ERANGE.

Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20181206151856.77503-1-eblake@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
This commit is contained in:
Eric Blake 2018-12-06 09:18:56 -06:00 committed by Laurent Vivier
parent 9e722ebc06
commit 53a90b9724

View file

@ -280,6 +280,7 @@ int qemu_strtosz_metric(const char *nptr, char **end, uint64_t *result)
static int check_strtox_error(const char *nptr, char *ep,
const char **endptr, int libc_errno)
{
assert(ep >= nptr);
if (endptr) {
*endptr = ep;
}
@ -327,6 +328,7 @@ int qemu_strtoi(const char *nptr, const char **endptr, int base,
char *ep;
long long lresult;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -379,6 +381,7 @@ int qemu_strtoui(const char *nptr, const char **endptr, int base,
char *ep;
long long lresult;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -435,6 +438,7 @@ int qemu_strtol(const char *nptr, const char **endptr, int base,
{
char *ep;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -477,6 +481,7 @@ int qemu_strtoul(const char *nptr, const char **endptr, int base,
{
char *ep;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -504,6 +509,7 @@ int qemu_strtoi64(const char *nptr, const char **endptr, int base,
{
char *ep;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -527,6 +533,7 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base,
{
char *ep;
assert((unsigned) base <= 36 && base != 1);
if (!nptr) {
if (endptr) {
*endptr = nptr;
@ -594,6 +601,7 @@ int parse_uint(const char *s, unsigned long long *value, char **endptr,
char *endp = (char *)s;
unsigned long long val = 0;
assert((unsigned) base <= 36 && base != 1);
if (!s) {
r = -EINVAL;
goto out;