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NFSv4: Ensure that idmap_pipe_downcall sanity-checks the downcall data

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Use the idmapper upcall data to verify that the legacy idmapper daemon
is indeed responding to an upcall that we sent.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
This commit is contained in:
Trond Myklebust 2012-09-27 16:15:00 -04:00
parent e9ab41b620
commit 0cac120233
1 changed files with 37 additions and 25 deletions
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62
fs/nfs/idmap.c
View file

@ -55,18 +55,19 @@
static const struct cred *id_resolver_cache;
static struct key_type key_type_id_resolver_legacy;
struct idmap {
struct rpc_pipe *idmap_pipe;
struct key_construction *idmap_key_cons;
struct mutex idmap_mutex;
};
struct idmap_legacy_upcalldata {
struct rpc_pipe_msg pipe_msg;
struct idmap_msg idmap_msg;
struct key_construction *key_cons;
struct idmap *idmap;
};
struct idmap {
struct rpc_pipe *idmap_pipe;
struct idmap_legacy_upcalldata *idmap_upcall_data;
struct mutex idmap_mutex;
};
/**
* nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
* @fattr: fully initialised struct nfs_fattr
@ -663,29 +664,30 @@ out:
static bool
nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
struct key_construction *cons)
struct idmap_legacy_upcalldata *data)
{
if (idmap->idmap_key_cons != NULL) {
if (idmap->idmap_upcall_data != NULL) {
WARN_ON_ONCE(1);
return false;
}
idmap->idmap_key_cons = cons;
idmap->idmap_upcall_data = data;
return true;
}
static void
nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
{
struct key_construction *cons = idmap->idmap_key_cons;
struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
idmap->idmap_key_cons = NULL;
kfree(idmap->idmap_upcall_data);
idmap->idmap_upcall_data = NULL;
complete_request_key(cons, ret);
}
static void
nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
{
if (idmap->idmap_key_cons != NULL)
if (idmap->idmap_upcall_data != NULL)
nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
}
@ -714,14 +716,12 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
goto out2;
ret = -EAGAIN;
if (!nfs_idmap_prepare_pipe_upcall(idmap, cons))
if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
goto out2;
ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
if (ret < 0) {
if (ret < 0)
nfs_idmap_abort_pipe_upcall(idmap, ret);
kfree(data);
}
return ret;
out2:
@ -738,21 +738,32 @@ static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *dat
authkey);
}
static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
struct idmap_msg *upcall,
struct key *key, struct key *authkey)
{
char id_str[NFS_UINT_MAXLEN];
int ret = -EINVAL;
int ret = -ENOKEY;
/* ret = -ENOKEY */
if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
goto out;
switch (im->im_conv) {
case IDMAP_CONV_NAMETOID:
if (strcmp(upcall->im_name, im->im_name) != 0)
break;
sprintf(id_str, "%d", im->im_id);
ret = nfs_idmap_instantiate(key, authkey, id_str);
break;
case IDMAP_CONV_IDTONAME:
if (upcall->im_id != im->im_id)
break;
ret = nfs_idmap_instantiate(key, authkey, im->im_name);
break;
default:
ret = -EINVAL;
}
out:
return ret;
}
@ -770,10 +781,11 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
* will have been woken up and someone else may now have used
* idmap_key_cons - so after this point we may no longer touch it.
*/
cons = idmap->idmap_key_cons;
if (cons == NULL)
if (idmap->idmap_upcall_data == NULL)
goto out_noupcall;
cons = idmap->idmap_upcall_data->key_cons;
if (mlen != sizeof(im)) {
ret = -ENOSPC;
goto out;
@ -793,9 +805,11 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
ret = -EINVAL;
goto out;
}
}
ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
ret = nfs_idmap_read_and_verify_message(&im,
&idmap->idmap_upcall_data->idmap_msg,
cons->key, cons->authkey);
if (ret >= 0) {
key_set_timeout(cons->key, nfs_idmap_cache_timeout);
ret = mlen;
@ -817,8 +831,6 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
if (msg->errno)
nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
/* Free memory allocated in nfs_idmap_legacy_upcall() */
kfree(data);
}
static void