krb5 commit: Fix various integer issues
Greg Hudson
ghudson at MIT.EDU
Mon Dec 10 14:21:21 EST 2012
https://github.com/krb5/krb5/commit/d3c5450ddf0b20855e86dab41735d56c6860156b
commit d3c5450ddf0b20855e86dab41735d56c6860156b
Author: Greg Hudson <ghudson at mit.edu>
Date: Mon Dec 10 14:18:30 2012 -0500
Fix various integer issues
In kdc_util.c and spnego_mech.c, error returns from ASN.1 length
functions could be ignored because they were assigned to unsigned
values. In spnego_mech.c, two buffer size checks could be rewritten
to reduce the likelihood of pointer overflow. In dump.c and
kdc_preauth.c, calloc() could be used to simplify the code and avoid
multiplication overflow. In pkinit_clnt.c, the wrong value was
checked for a null result from malloc(), and the code could be
simplified.
Reported by Nickolai Zeldovich <nickolai at csail.mit.edu>.
ticket: 7488
src/kadmin/dbutil/dump.c | 3 +-
src/kdc/kdc_preauth.c | 3 +-
src/kdc/kdc_util.c | 3 +-
src/lib/gssapi/spnego/spnego_mech.c | 6 ++--
src/plugins/preauth/pkinit/pkinit_clnt.c | 43 ++++++++---------------------
5 files changed, 19 insertions(+), 39 deletions(-)
diff --git a/src/kadmin/dbutil/dump.c b/src/kadmin/dbutil/dump.c
index cbd2d47..7b515bd 100644
--- a/src/kadmin/dbutil/dump.c
+++ b/src/kadmin/dbutil/dump.c
@@ -2109,7 +2109,7 @@ process_k5beta6_record(char *fname, krb5_context kcontext, FILE *filep,
dbentry->n_tl_data = t3;
/* Get memory for key list */
- if (t4 && (kp = malloc(t4*sizeof(krb5_key_data))) == NULL)
+ if (t4 && (kp = calloc(t4, sizeof(krb5_key_data))) == NULL)
goto cleanup;
/* Get memory for extra data */
@@ -2121,7 +2121,6 @@ process_k5beta6_record(char *fname, krb5_context kcontext, FILE *filep,
dbentry->e_length = t5;
if (kp != NULL) {
- memset(kp, 0, t4*sizeof(krb5_key_data));
dbentry->key_data = kp;
kp = NULL;
}
diff --git a/src/kdc/kdc_preauth.c b/src/kdc/kdc_preauth.c
index 29485a3..42a37a8 100644
--- a/src/kdc/kdc_preauth.c
+++ b/src/kdc/kdc_preauth.c
@@ -470,11 +470,10 @@ client_keys(krb5_context context, krb5_kdcpreauth_rock rock,
krb5_key_data *entry_key;
int i, k;
- keys = malloc(sizeof(krb5_keyblock) * (request->nktypes + 1));
+ keys = calloc(request->nktypes + 1, sizeof(krb5_keyblock));
if (keys == NULL)
return ENOMEM;
- memset(keys, 0, sizeof(krb5_keyblock) * (request->nktypes + 1));
k = 0;
for (i = 0; i < request->nktypes; i++) {
entry_key = NULL;
diff --git a/src/kdc/kdc_util.c b/src/kdc/kdc_util.c
index ea11f54..a6a53a1 100644
--- a/src/kdc/kdc_util.c
+++ b/src/kdc/kdc_util.c
@@ -842,9 +842,10 @@ fetch_asn1_field(unsigned char *astream, unsigned int level,
/* return length and data */
astream++;
savelen = *astream;
- if ((data->length = asn1length(&astream)) < 0) {
+ if ((length = asn1length(&astream)) < 0) {
return(-1);
}
+ data->length = length;
/* if the field length is indefinite, we will have to subtract two
(terminating octets) from the length returned since we don't want
to pass any info from the "wrapper" back. asn1length will always return
diff --git a/src/lib/gssapi/spnego/spnego_mech.c b/src/lib/gssapi/spnego/spnego_mech.c
index 812c16d..696f42d 100644
--- a/src/lib/gssapi/spnego/spnego_mech.c
+++ b/src/lib/gssapi/spnego/spnego_mech.c
@@ -3998,7 +3998,7 @@ g_verify_neg_token_init(unsigned char **buf_in, unsigned int cur_size)
{
unsigned char *buf = *buf_in;
unsigned char *endptr = buf + cur_size;
- unsigned int seqsize;
+ int seqsize;
int ret = 0;
unsigned int bytes;
@@ -4022,7 +4022,7 @@ g_verify_neg_token_init(unsigned char **buf_in, unsigned int cur_size)
/*
* Make sure we have the entire buffer as described
*/
- if (buf + seqsize > endptr)
+ if (seqsize > endptr - buf)
return (G_BAD_TOK_HEADER);
} else {
return (G_BAD_TOK_HEADER);
@@ -4039,7 +4039,7 @@ g_verify_neg_token_init(unsigned char **buf_in, unsigned int cur_size)
/*
* Make sure we have the entire buffer as described
*/
- if (buf + bytes > endptr)
+ if (seqsize > endptr - buf)
return (G_BAD_TOK_HEADER);
} else {
return (G_BAD_TOK_HEADER);
diff --git a/src/plugins/preauth/pkinit/pkinit_clnt.c b/src/plugins/preauth/pkinit/pkinit_clnt.c
index 7a069c1..75b97c6 100644
--- a/src/plugins/preauth/pkinit/pkinit_clnt.c
+++ b/src/plugins/preauth/pkinit/pkinit_clnt.c
@@ -1406,40 +1406,21 @@ pkinit_client_plugin_fini(krb5_context context, krb5_clpreauth_moddata moddata)
static krb5_error_code
add_string_to_array(krb5_context context, char ***array, const char *addition)
{
- char **out = NULL;
-
- if (*array == NULL) {
- out = malloc(2 * sizeof(char *));
- if (out == NULL)
- return ENOMEM;
- out[1] = NULL;
- out[0] = strdup(addition);
- if (out[0] == NULL) {
- free(out);
- return ENOMEM;
- }
- } else {
- int i;
- char **a = *array;
- for (i = 0; a[i] != NULL; i++);
- out = malloc( (i + 2) * sizeof(char *));
- if (out == NULL)
- return ENOMEM;
- for (i = 0; a[i] != NULL; i++) {
- out[i] = a[i];
- }
- out[i++] = strdup(addition);
- if (out == NULL) {
- free(out);
- return ENOMEM;
- }
- out[i] = NULL;
- free(*array);
- }
- *array = out;
+ char **a = *array;
+ size_t len;
+ for (len = 0; a != NULL && a[len] != NULL; len++);
+ a = realloc(a, (len + 2) * sizeof(char *));
+ if (a == NULL)
+ return ENOMEM;
+ *array = a;
+ a[len] = strdup(addition);
+ if (a[len] == NULL)
+ return ENOMEM;
+ a[len + 1] = NULL;
return 0;
}
+
static krb5_error_code
handle_gic_opt(krb5_context context,
pkinit_context plgctx,
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