6.6-stable review patch. If anyone has any objections, please let me know.
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From: Fedor Pchelkin pchelkin@ispras.ru
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 --- drivers/s390/crypto/pkey_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/s390/crypto/pkey_api.c +++ b/drivers/s390/crypto/pkey_api.c @@ -1333,7 +1333,7 @@ static void *_copy_apqns_from_user(void if (!uapqns || nr_apqns == 0) return NULL;
- return memdup_user(uapqns, nr_apqns * sizeof(struct pkey_apqn)); + return memdup_array_user(uapqns, nr_apqns, sizeof(struct pkey_apqn)); }
static long pkey_unlocked_ioctl(struct file *filp, unsigned int cmd,