ksmbd: casefold utf-8 share names and fix ascii lowercase conversion
strtolower() corrupts all UTF-8 share names that have a byte in the C0
(À ISO8859-1) to DE (Þ ISO8859-1) range, since the non-ASCII part of
ISO8859-1 is incompatible with UTF-8. Prevent this by checking that a
byte is in the ASCII range with isascii(), before the conversion to
lowercase with tolower(). Properly handle case-insensitivity of UTF-8
share names by casefolding them, but fallback to ASCII lowercase
conversion on failure or if CONFIG_UNICODE is not set. Refactor to move
the share name casefolding immediately after the share name extraction.
Also, make the associated constness corrections.
Signed-off-by: Atte Heikkilä <atteh.mailbox@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index 756ad63..12be838 100644
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -60,6 +60,12 @@ struct ksmbd_conn *ksmbd_conn_alloc(void)
conn->local_nls = load_nls("utf8");
if (!conn->local_nls)
conn->local_nls = load_nls_default();
+ if (IS_ENABLED(CONFIG_UNICODE))
+ conn->um = utf8_load(UNICODE_AGE(12, 1, 0));
+ else
+ conn->um = ERR_PTR(-EOPNOTSUPP);
+ if (IS_ERR(conn->um))
+ conn->um = NULL;
atomic_set(&conn->req_running, 0);
atomic_set(&conn->r_count, 0);
conn->total_credits = 1;
@@ -350,6 +356,8 @@ int ksmbd_conn_handler_loop(void *p)
wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);
+ if (IS_ENABLED(CONFIG_UNICODE))
+ utf8_unload(conn->um);
unload_nls(conn->local_nls);
if (default_conn_ops.terminate_fn)
default_conn_ops.terminate_fn(conn);
