On 11/06/2025 21:20, Fedor Pchelkin wrote:
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