From 2b7a8dc06d0f840345ae3c7ed6f9d55962b5f54a Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 1 Jul 2021 16:22:21 +0200 Subject: s390/dasd: Avoid field over-reading memcpy() In preparation for FORTIFY_SOURCE performing compile-time and run-time field array bounds checking for memcpy(), memmove(), and memset(), avoid intentionally reading across neighboring array fields. Add a wrapping structure to serve as the memcpy() source, so the compiler can do appropriate bounds checking, avoiding this future warning: In function '__fortify_memcpy', inlined from 'create_uid' at drivers/s390/block/dasd_eckd.c:749:2: ./include/linux/fortify-string.h:246:4: error: call to '__read_overflow2_field' declared with attribute error: detected read beyond size of field (2nd parameter) Signed-off-by: Kees Cook Signed-off-by: Stefan Haberland Link: https://lore.kernel.org/r/20210701142221.3408680-3-sth@linux.ibm.com Signed-off-by: Jens Axboe --- drivers/s390/block/dasd_eckd.c | 2 +- drivers/s390/block/dasd_eckd.h | 6 ++++-- 2 files changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index a6ac505cbdd7..0de1a463c509 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -746,7 +746,7 @@ static void create_uid(struct dasd_eckd_private *private) memcpy(uid->vendor, private->ned->HDA_manufacturer, sizeof(uid->vendor) - 1); EBCASC(uid->vendor, sizeof(uid->vendor) - 1); - memcpy(uid->serial, private->ned->HDA_location, + memcpy(uid->serial, &private->ned->serial, sizeof(uid->serial) - 1); EBCASC(uid->serial, sizeof(uid->serial) - 1); uid->ssid = private->gneq->subsystemID; diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h index 73651211789f..65e4630ad2ae 100644 --- a/drivers/s390/block/dasd_eckd.h +++ b/drivers/s390/block/dasd_eckd.h @@ -332,8 +332,10 @@ struct dasd_ned { __u8 dev_type[6]; __u8 dev_model[3]; __u8 HDA_manufacturer[3]; - __u8 HDA_location[2]; - __u8 HDA_seqno[12]; + struct { + __u8 HDA_location[2]; + __u8 HDA_seqno[12]; + } serial; __u8 ID; __u8 unit_addr; } __attribute__ ((packed)); -- cgit v1.2.3