userns: Convert usb functionfs to use kuid/kgid where appropriate

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 8adc79d1b402..f9ee4e08a4a8 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -220,8 +220,8 @@ struct ffs_data {
         /* File permissions, written once when fs is mounted */
         struct ffs_file_perms {
                 umode_t                         mode;
-                uid_t                           uid;
-                gid_t                           gid;
+                kuid_t                          uid;
+                kgid_t                          gid;
         }                               file_perms;
 
         /*
@@ -1143,10 +1143,19 @@ static int ffs_fs_parse_opts(struct ffs_sb_fill_data *data, char *opts)
                         break;
 
                 case 3:
-                        if (!memcmp(opts, "uid", 3))
-                                data->perms.uid = value;
+                        if (!memcmp(opts, "uid", 3)) {
+                                data->perms.uid = make_kuid(current_user_ns(), value);
+                                if (!uid_valid(data->perms.uid)) {
+                                        pr_err("%s: unmapped value: %lu\n", opts, value);
+                                        return -EINVAL;
+                                }
+                        }
                         else if (!memcmp(opts, "gid", 3))
-                                data->perms.gid = value;
+                                data->perms.gid = make_kgid(current_user_ns(), value);
+                                if (!gid_valid(data->perms.gid)) {
+                                        pr_err("%s: unmapped value: %lu\n", opts, value);
+                                        return -EINVAL;
+                                }
                         else
                                 goto invalid;
                         break;
@@ -1175,8 +1184,8 @@ ffs_fs_mount(struct file_system_type *t, int flags,
         struct ffs_sb_fill_data data = {
                 .perms = {
                         .mode = S_IFREG | 0600,
-                        .uid = 0,
-                        .gid = 0
+                        .uid = GLOBAL_ROOT_UID,
+                        .gid = GLOBAL_ROOT_GID,
                 },
                 .root_mode = S_IFDIR | 0500,
         };