commit 70bccd9855dae56942f2b18a08ba137bb54093a0
author Makar Semyonov <m.semenov@tssltd.ru> Thu Sep 04 15:28:41 2025 +0300
committer Steve French <stfrench@microsoft.com> Thu Sep 04 11:43:31 2025 -0500
tree b3a165f697f4ddcf9bda392999aef504753c51ec
parent 91be128b496c0de60a7dceb70d34935a29d38bbd

cifs: prevent NULL pointer dereference in UTF16 conversion

There can be a NULL pointer dereference bug here. NULL is passed to
__cifs_sfu_make_node without checks, which passes it unchecked to
cifs_strndup_to_utf16, which in turn passes it to
cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash.

This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and
returns NULL early to prevent dereferencing NULL pointer.

Found by Linux Verification Center (linuxtesting.org) with SVACE

Signed-off-by: Makar Semyonov <m.semenov@tssltd.ru>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>