diff options
| -rw-r--r-- | fs/cifs/cifsacl.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index f4508ee4e80d..751d34bd825c 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); |