[PATCH v3][next] scsi: lpfc: Use struct_size() helper

Justin Tee
2023-05-31T22:22:59Z

Prefer struct_size() over open-coded versions of idiom:

sizeof(struct-with-flex-array) + sizeof(typeof-flex-array-elements) * count

where count is the max number of items the flexible array is supposed to
contain.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
---
Changes in v3:
- Instead of hardcode to 1, use be32_to_cpu(rap->no_of_objects).
(Justin Tee).

v2:
- Use literal 1 in call to struct_size(), instead of rap->no_of_objects
(Kees Cook).

v1:
- Link:
https://lore.kernel.org/linux-hardening/99e06733f5f35c6cd62e05f530b93107bfd03362.1684358315.git.gustavoars@kernel.org/
---
drivers/scsi/lpfc/lpfc_ct.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_ct.c b/drivers/scsi/lpfc/lpfc_ct.c
index e880d127d7f5..703429512ead 100644
--- a/drivers/scsi/lpfc/lpfc_ct.c
+++ b/drivers/scsi/lpfc/lpfc_ct.c
@@ -3748,8 +3748,7 @@ lpfc_vmid_cmd(struct lpfc_vport *vport,
rap->obj[0].entity_id_len = vmid->vmid_len;
memcpy(rap->obj[0].entity_id, vmid->host_vmid, vmid->vmid_len);
size = RAPP_IDENT_OFFSET +
- sizeof(struct lpfc_vmid_rapp_ident_list) +
- sizeof(struct entity_id_object);
+ struct_size(rap, obj, be32_to_cpu(rap->no_of_objects));
retry = 1;
break;

@@ -3768,8 +3767,7 @@ lpfc_vmid_cmd(struct lpfc_vport *vport,
dap->obj[0].entity_id_len = vmid->vmid_len;
memcpy(dap->obj[0].entity_id, vmid->host_vmid, vmid->vmid_len);
size = DAPP_IDENT_OFFSET +
- sizeof(struct lpfc_vmid_dapp_ident_list) +
- sizeof(struct entity_id_object);
+ struct_size(dap, obj, be32_to_cpu(dap->no_of_objects));
write_lock(&vport->vmid_lock);
vmid->flag &= ~LPFC_VMID_REGISTERED;
write_unlock(&vport->vmid_lock);
--
2.38.0