aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--fs/cifs/cifsacl.c23
1 files changed, 19 insertions, 4 deletions
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index f4508ee4e80..751d34bd825 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -49,6 +49,20 @@ cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
{
char *payload;
+ /*
+ * If the payload is less than or equal to the size of a pointer, then
+ * an allocation here is wasteful. Just copy the data directly to the
+ * payload.value union member instead.
+ *
+ * With this however, you must check the datalen before trying to
+ * dereference payload.data!
+ */
+ if (prep->datalen <= sizeof(void *)) {
+ key->payload.value = 0;
+ memcpy(&key->payload.value, prep->data, prep->datalen);
+ key->datalen = prep->datalen;
+ return 0;
+ }
payload = kmalloc(prep->datalen, GFP_KERNEL);
if (!payload)
return -ENOMEM;
@@ -62,7 +76,8 @@ cifs_idmap_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
static inline void
cifs_idmap_key_destroy(struct key *key)
{
- kfree(key->payload.data);
+ if (key->datalen > sizeof(void *))
+ kfree(key->payload.data);
}
static struct key_type cifs_idmap_key_type = {
@@ -245,7 +260,7 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
* probably a safe assumption but might be better to check based on
* sidtype.
*/
- if (sidkey->datalen < sizeof(uid_t)) {
+ if (sidkey->datalen != sizeof(uid_t)) {
rc = -EIO;
cFYI(1, "%s: Downcall contained malformed key "
"(datalen=%hu)", __func__, sidkey->datalen);
@@ -253,9 +268,9 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
}
if (sidtype == SIDOWNER)
- fuid = *(uid_t *)sidkey->payload.value;
+ memcpy(&fuid, &sidkey->payload.value, sizeof(uid_t));
else
- fgid = *(gid_t *)sidkey->payload.value;
+ memcpy(&fgid, &sidkey->payload.value, sizeof(gid_t));
out_key_put:
key_put(sidkey);