NetLabel: better error handling involving mls_export_cat()
Upon inspection it looked like the error handling for mls_export_cat() was
rather poor. This patch addresses this by NULL'ing out kfree()'d pointers
before returning and checking the return value of the function everywhere
it is called.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
index cfed1d3..d539346 100644
--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -93,11 +93,15 @@
size_t bitmap_byte;
unsigned char bitmask;
+ if (src->highbit == 0) {
+ *dst = NULL;
+ *dst_len = 0;
+ return 0;
+ }
+
bitmap_len = src->highbit / 8;
if (src->highbit % 7)
bitmap_len += 1;
- if (bitmap_len == 0)
- return -EINVAL;
bitmap = kzalloc((bitmap_len & ~(sizeof(MAPTYPE) - 1)) +
sizeof(MAPTYPE),
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index c713af2..2cca8e2 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -640,8 +640,13 @@
{
int rc = -EPERM;
- if (!selinux_mls_enabled)
+ if (!selinux_mls_enabled) {
+ *low = NULL;
+ *low_len = 0;
+ *high = NULL;
+ *high_len = 0;
return 0;
+ }
if (low != NULL) {
rc = ebitmap_export(&context->range.level[0].cat,
@@ -661,10 +666,16 @@
return 0;
export_cat_failure:
- if (low != NULL)
+ if (low != NULL) {
kfree(*low);
- if (high != NULL)
+ *low = NULL;
+ *low_len = 0;
+ }
+ if (high != NULL) {
kfree(*high);
+ *high = NULL;
+ *high_len = 0;
+ }
return rc;
}
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 18274b0..b1f6fb3 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2399,31 +2399,33 @@
if (!ss_initialized)
return 0;
+ netlbl_secattr_init(&secattr);
+
POLICY_RDLOCK;
ctx = sidtab_search(&sidtab, sid);
if (ctx == NULL)
goto netlbl_socket_setsid_return;
- netlbl_secattr_init(&secattr);
secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
GFP_ATOMIC);
mls_export_lvl(ctx, &secattr.mls_lvl, NULL);
secattr.mls_lvl_vld = 1;
- mls_export_cat(ctx,
- &secattr.mls_cat,
- &secattr.mls_cat_len,
- NULL,
- NULL);
+ rc = mls_export_cat(ctx,
+ &secattr.mls_cat,
+ &secattr.mls_cat_len,
+ NULL,
+ NULL);
+ if (rc != 0)
+ goto netlbl_socket_setsid_return;
rc = netlbl_socket_setattr(sock, &secattr);
if (rc == 0)
sksec->nlbl_state = NLBL_LABELED;
- netlbl_secattr_destroy(&secattr);
-
netlbl_socket_setsid_return:
POLICY_RDUNLOCK;
+ netlbl_secattr_destroy(&secattr);
return rc;
}