summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--fs/nfs/nfs4super.c2
-rw-r--r--fs/nfs/super.c80
2 files changed, 44 insertions, 38 deletions
diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 569b166cc050..a5e1a3026d48 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -252,6 +252,8 @@ struct dentry *nfs4_try_mount(int flags, const char *dev_name,
dfprintk(MOUNT, "--> nfs4_try_mount()\n");
+ if (data->auth_flavors[0] == RPC_AUTH_MAXFLAVOR)
+ data->auth_flavors[0] = RPC_AUTH_UNIX;
export_path = data->nfs_server.export_path;
data->nfs_server.export_path = "/";
root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 17b32b722457..3bb8318f6d0c 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -917,7 +917,7 @@ static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
data->mount_server.port = NFS_UNSPEC_PORT;
data->nfs_server.port = NFS_UNSPEC_PORT;
data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
- data->auth_flavors[0] = RPC_AUTH_UNIX;
+ data->auth_flavors[0] = RPC_AUTH_MAXFLAVOR;
data->auth_flavor_len = 1;
data->minorversion = 0;
data->need_mount = true;
@@ -1605,49 +1605,57 @@ out_security_failure:
}
/*
- * Match the requested auth flavors with the list returned by
- * the server. Returns zero and sets the mount's authentication
- * flavor on success; returns -EACCES if server does not support
- * the requested flavor.
+ * Select a security flavor for this mount. The selected flavor
+ * is planted in args->auth_flavors[0].
*/
-static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
- struct nfs_mount_request *request)
+static void nfs_select_flavor(struct nfs_parsed_mount_data *args,
+ struct nfs_mount_request *request)
{
- unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
+ unsigned int i, count = *(request->auth_flav_len);
+ rpc_authflavor_t flavor;
+
+ if (args->auth_flavors[0] != RPC_AUTH_MAXFLAVOR)
+ goto out;
+
+ /*
+ * The NFSv2 MNT operation does not return a flavor list.
+ */
+ if (args->mount_server.version != NFS_MNT3_VERSION)
+ goto out_default;
/*
* Certain releases of Linux's mountd return an empty
- * flavor list. To prevent behavioral regression with
- * these servers (ie. rejecting mounts that used to
- * succeed), revert to pre-2.6.32 behavior (no checking)
- * if the returned flavor list is empty.
+ * flavor list in some cases.
*/
- if (server_authlist_len == 0)
- return 0;
+ if (count == 0)
+ goto out_default;
/*
- * We avoid sophisticated negotiating here, as there are
- * plenty of cases where we can get it wrong, providing
- * either too little or too much security.
- *
* RFC 2623, section 2.7 suggests we SHOULD prefer the
* flavor listed first. However, some servers list
- * AUTH_NULL first. Our caller plants AUTH_SYS, the
- * preferred default, in args->auth_flavors[0] if user
- * didn't specify sec= mount option.
+ * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
*/
- for (i = 0; i < args->auth_flavor_len; i++)
- for (j = 0; j < server_authlist_len; j++)
- if (args->auth_flavors[i] == request->auth_flavs[j]) {
- dfprintk(MOUNT, "NFS: using auth flavor %d\n",
- request->auth_flavs[j]);
- args->auth_flavors[0] = request->auth_flavs[j];
- return 0;
- }
+ for (i = 0; i < count; i++) {
+ struct rpcsec_gss_info info;
+
+ flavor = request->auth_flavs[i];
+ switch (flavor) {
+ case RPC_AUTH_UNIX:
+ goto out_set;
+ case RPC_AUTH_NULL:
+ continue;
+ default:
+ if (rpcauth_get_gssinfo(flavor, &info) == 0)
+ goto out_set;
+ }
+ }
- dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
- nfs_umount(request);
- return -EACCES;
+out_default:
+ flavor = RPC_AUTH_UNIX;
+out_set:
+ args->auth_flavors[0] = flavor;
+out:
+ dfprintk(MOUNT, "NFS: using auth flavor %d\n", args->auth_flavors[0]);
}
/*
@@ -1710,12 +1718,8 @@ static int nfs_request_mount(struct nfs_parsed_mount_data *args,
return status;
}
- /*
- * MNTv1 (NFSv2) does not support auth flavor negotiation.
- */
- if (args->mount_server.version != NFS_MNT3_VERSION)
- return 0;
- return nfs_walk_authlist(args, &request);
+ nfs_select_flavor(args, &request);
+ return 0;
}
struct dentry *nfs_try_mount(int flags, const char *dev_name,