To work around a misbehavior of the compiler's ability to see into composite flexible array structs (as detailed in the coming memcpy() hardening series[1]), split the memcpy() of the header and the payload so no false positive run-time overflow warning will be generated. [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@xxxxxxxxxxxx/ Cc: Alexandra Winter <wintera@xxxxxxxxxxxxx> Cc: Wenjia Zhang <wenjia@xxxxxxxxxxxxx> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx> Cc: Sven Schnelle <svens@xxxxxxxxxxxxx> Cc: linux-s390@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- drivers/s390/net/qeth_l2_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 2d4436cbcb47..0ce635b7b472 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -1530,8 +1530,8 @@ static void qeth_addr_change_event(struct qeth_card *card, else INIT_DELAYED_WORK(&data->dwork, qeth_l2_dev2br_worker); data->card = card; - memcpy(&data->ac_event, hostevs, - sizeof(struct qeth_ipacmd_addr_change) + extrasize); + data->ac_event = *hostevs; + memcpy(data->ac_event.entry, hostevs->entry, extrasize); queue_delayed_work(card->event_wq, &data->dwork, 0); } -- 2.34.1
