The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 7360ee47599af91a1d5f4e74d635d9408a54e489 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025062906-tightwad-overvalue-2006@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7360ee47599af91a1d5f4e74d635d9408a54e489 Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin pchelkin@ispras.ru Date: Wed, 11 Jun 2025 22:20:10 +0300 Subject: [PATCH] s390/pkey: Prevent overflow in size calculation for memdup_user()
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
diff --git a/drivers/s390/crypto/pkey_api.c b/drivers/s390/crypto/pkey_api.c index cef60770f68b..b3fcdcae379e 100644 --- a/drivers/s390/crypto/pkey_api.c +++ b/drivers/s390/crypto/pkey_api.c @@ -86,7 +86,7 @@ static void *_copy_apqns_from_user(void __user *uapqns, size_t nr_apqns) 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 int pkey_ioctl_genseck(struct pkey_genseck __user *ugs)