commit 7360ee47599af91a1d5f4e74d635d9408a54e489 upstream. Number of apqn target list entries contained in 'nr_apqns' variable is determined by userspace via an ioctl call so the result of the product in calculation of size passed to memdup_user() may overflow. In this case the actual size of the allocated area and the value describing it won't be in sync leading to various types of unpredictable behaviour later. Use a proper memdup_array_user() helper which returns an error if an overflow is detected. Note that it is different from when nr_apqns is initially zero - that case is considered valid and should be handled in subsequent pkey_handler implementations. Found by Linux Verification Center (linuxtesting.org). Fixes: f2bbc96e7cfa ("s390/pkey: add CCA AES cipher key support") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20250611192011.206057-1-pchelkin@ispras.ru Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>