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Commit c5066945 authored by Bryan Schumaker's avatar Bryan Schumaker Committed by Trond Myklebust
Browse files

NFS: Clear key construction data if the idmap upcall fails 



idmap_pipe_downcall already clears this field if the upcall succeeds,
but if it fails (rpc.idmapd isn't running) the field will still be set
on the next call triggering a BUG_ON().  This patch tries to handle all
possible ways that the upcall could fail and clear the idmap key data
for each one.

Signed-off-by: default avatarBryan Schumaker <bjschuma@netapp.com>
Tested-by: default avatarWilliam Dauchy <wdauchy@gmail.com>
Cc: stable@vger.kernel.org [>= 3.4]
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent cff298c7

fs/nfs/idmap.c

+42 −14
Original line number Diff line number Diff line
@@ -61,6 +61,12 @@ struct idmap { 
	struct mutex		idmap_mutex;

};



struct idmap_legacy_upcalldata {

	struct rpc_pipe_msg pipe_msg;

	struct idmap_msg idmap_msg;

	struct idmap *idmap;

};



/**

 * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields

 * @fattr: fully initialised struct nfs_fattr
@@ -324,6 +330,7 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen, 
		ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,

					    name, namelen, type, data,

					    data_size, idmap);

		idmap->idmap_key_cons = NULL;

		mutex_unlock(&idmap->idmap_mutex);

	}

	return ret;
@@ -380,11 +387,13 @@ static const match_table_t nfs_idmap_tokens = { 
static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);

static ssize_t idmap_pipe_downcall(struct file *, const char __user *,

				   size_t);

static void idmap_release_pipe(struct inode *);

static void idmap_pipe_destroy_msg(struct rpc_pipe_msg *);



static const struct rpc_pipe_ops idmap_upcall_ops = {

	.upcall		= rpc_pipe_generic_upcall,

	.downcall	= idmap_pipe_downcall,

	.release_pipe	= idmap_release_pipe,

	.destroy_msg	= idmap_pipe_destroy_msg,

};
@@ -616,7 +625,8 @@ void nfs_idmap_quit(void) 
	nfs_idmap_quit_keyring();

}



static int nfs_idmap_prepare_message(char *desc, struct idmap_msg *im,

static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,

				     struct idmap_msg *im,

				     struct rpc_pipe_msg *msg)

{

	substring_t substr;
@@ -659,6 +669,7 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, 
				   const char *op,

				   void *aux)

{

	struct idmap_legacy_upcalldata *data;

	struct rpc_pipe_msg *msg;

	struct idmap_msg *im;

	struct idmap *idmap = (struct idmap *)aux;
@@ -666,15 +677,15 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, 
	int ret = -ENOMEM;



	/* msg and im are freed in idmap_pipe_destroy_msg */

	msg = kmalloc(sizeof(*msg), GFP_KERNEL);

	if (!msg)

		goto out0;



	im = kmalloc(sizeof(*im), GFP_KERNEL);

	if (!im)

	data = kmalloc(sizeof(*data), GFP_KERNEL);

	if (!data)

		goto out1;



	ret = nfs_idmap_prepare_message(key->description, im, msg);

	msg = &data->pipe_msg;

	im = &data->idmap_msg;

	data->idmap = idmap;



	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);

	if (ret < 0)

		goto out2;
@@ -683,15 +694,15 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, 


	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);

	if (ret < 0)

		goto out2;

		goto out3;



	return ret;



out3:

	idmap->idmap_key_cons = NULL;

out2:

	kfree(im);

	kfree(data);

out1:

	kfree(msg);

out0:

	complete_request_key(cons, ret);

	return ret;

}
@@ -775,9 +786,26 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen) 
static void

idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)

{

	struct idmap_legacy_upcalldata *data = container_of(msg,

			struct idmap_legacy_upcalldata,

			pipe_msg);

	struct idmap *idmap = data->idmap;

	struct key_construction *cons;

	if (msg->errno) {

		cons = ACCESS_ONCE(idmap->idmap_key_cons);

		idmap->idmap_key_cons = NULL;

		complete_request_key(cons, msg->errno);

	}

	/* Free memory allocated in nfs_idmap_legacy_upcall() */

	kfree(msg->data);

	kfree(msg);

	kfree(data);

}



static void

idmap_release_pipe(struct inode *inode)

{

	struct rpc_inode *rpci = RPC_I(inode);

	struct idmap *idmap = (struct idmap *)rpci->private;

	idmap->idmap_key_cons = NULL;

}



int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)