userns: Check uid_map's opener's fsuid, not the current fsuid
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index e2d4ace..5c16f3a 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -797,12 +797,12 @@
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;
}
}
