userns: Check uid_map's opener's fsuid, not the current fsuid

Signed-off-by: Andy Lutomirski <luto@amacapital.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index e2d4ace4481b..5c16f3aa757a 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -797,12 +797,12 @@ static bool new_idmap_permitted(const struct file *file,
                 u32 id = new_map->extent[0].lower_first;
                 if (cap_setid == CAP_SETUID) {
                         kuid_t uid = make_kuid(ns->parent, id);
-                        if (uid_eq(uid, current_fsuid()))
+                        if (uid_eq(uid, file->f_cred->fsuid))
                                 return true;
                 }
                 else if (cap_setid == CAP_SETGID) {
                         kgid_t gid = make_kgid(ns->parent, id);
-                        if (gid_eq(gid, current_fsgid()))
+                        if (gid_eq(gid, file->f_cred->fsgid))
                                 return true;
                 }
         }