[PATCH v2][next] scsi: smartpqi: Replace one-element array with flexible-array member

Gustavo A. R. Silva
2023-02-07T16:57:21Z

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct report_log_lun_list.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/204
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v2:
In v1 we thought that the original code was allocating one too-many
entries for the list. However, Don Brance commented that the allocation
was actually intentional[1]. So, I added a code comment with his feedback.
Link: https://lore.kernel.org/linux-hardening/16e6c434-44af-2efb-d4bc-a253e93e5590@embeddedor.com/ [1]

v1:
Link: https://lore.kernel.org/linux-hardening/c80c0979933e0c05e80d95792ef167a28640a14b.1663816572.git.gustavoars@kernel.org/

drivers/scsi/smartpqi/smartpqi.h | 2 +-
drivers/scsi/smartpqi/smartpqi_init.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h
index af27bb0f3133..228838eb3686 100644
--- a/drivers/scsi/smartpqi/smartpqi.h
+++ b/drivers/scsi/smartpqi/smartpqi.h
@@ -954,7 +954,7 @@ struct report_log_lun {

struct report_log_lun_list {
struct report_lun_header header;
- struct report_log_lun lun_entries[1];
+ struct report_log_lun lun_entries[];
};

struct report_phys_lun_8byte_wwid {
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c
index d0446d4d4465..af8f1a8e9f8f 100644
--- a/drivers/scsi/smartpqi/smartpqi_init.c
+++ b/drivers/scsi/smartpqi/smartpqi_init.c
@@ -1277,6 +1277,10 @@ static int pqi_get_device_lists(struct pqi_ctrl_info *ctrl_info,
logdev_data_length = sizeof(struct report_lun_header) +
logdev_list_length;

+ /*
+ * Notice that we take on an extra list entry (struct report_log_lun)
+ * that is all zeros for the controller itself.
+ */
internal_logdev_list = kmalloc(logdev_data_length +
sizeof(struct report_log_lun), GFP_KERNEL);
if (!internal_logdev_list) {
--
2.34.1